Croatian Bureau of Statistics

Industry Statistics Department

Croatian Bureau of Statistics, Ilica 3, 10000 ZAGREB, CROATIA

The industrial producer price index (PPI) is an important short-term indicator of the business cycle that shows monthly price changes in the total industrial sector (the NKD 2007. sections B, C, D and E – only division 36), on the domestic and non-domestic market. PPI is an important business indicator that permits monthly monitoring of prices at different stages of the manufacturing process. It is also a mean of distinguishing the effective growth of an activity due to price changes, provides information to the business community on particular markets of their interest. It may indicate inflationary changes before they reach consumers.

PPI indices are presented in gross (unadjusted) form. They were calculated on the basis of data collected through the  Monthly Survey on Industrial Producer Prices (IND-3/KPS/M e-form).

The PPI total is composed of two sub-indices, that is, the industrial producer price index on the domestic market and the industrial producer price index on the non-domestic market. The combination of sub-indices for these two markets provides changes in given products/services, while their aggregation provides divisions of products and activities.

PPI total measures changes of producer prices of manufactured goods produced in the Republic of Croatia and sold by producers on the domestic (Croatian) and/or non-domestic (non--Croatian) market.

PPI on the domestic market measure changes of producer prices of manufactured goods that are produced and sold by producers on the domestic (Croatian) market.

PPI on non-domestic market measure changes in the level of producer prices of manufactured goods that are sold by producers on foreign (non-Croatian) markets

Producers’ prices of industrial products have been collected by reporting units’ classified according to the National Classification of Activities - NKD 2007. (=NACE Rev.2). For selection of reporting units: enterprises and local units, classification of activity -NKD 2007 (=NACE Rev.2) are in use, and for selection of product/items: classification of products and services - KPD 2015 (=CPA 2015) are in use, and more detailed nomenclature for PRODCOM based annual survey by the NIP (10-digit levels, identical to 6-digit levels with KPD 2015 with more detailed breakdowns to the national aggregation of PRODCOM List) are in use.

The reporting units included in the IND-3/KPS/M Survey are selected enterprises (legal entities and tradesmen) that produce selected products as defined in the Nomenclature of Industrial Products – NIP 2021., classified in the NKD 2007. activity sections B Mining and quarrying, C Manufacturing, D Electricity, gas, steam and air conditioning supply and E Water supply; sewerage, waste management and remediation activities (only division 36).

In order to collect data on industrial producer prices on the domestic and non-domestic market, the IND-3/KPS/M Survey for 2022 covers a representative sample of industrial products at the level of covered activity classes of the NKD 2007., that is, all products exceeding 20 million kuna on the domestic market and 15 million kuna on the non-domestic market according to the results of the PRODCOM Survey on Industrial Production (IND-21/PRODCOM/G form) for 2021, while the selection of enterprises has been done according to their share in the production of selected products, separately for domestic and non-domestic market.

Industrial coverage: The PPI covers the commodities classified under NACE Rev.2 sections B to E (division 36 only).

Product coverage: for monitoring of the PPI on the domestic market, the sample for the IND-3/KPS/M Survey for 2022 covers 2021 item prices within the selected NIP 2021. products in 1191 enterprises (legal entities and tradesmen), while for monitoring of the PPI on the non-domestic market it covers 1198 item prices within the selected NIP 2021. products in 712 enterprises (legal entities and tradesmen) - both with state of 15th of the reference month.

The Industrial Producers’ Price Index (PPI) is to measure of changes in producers’ prices of a fixed set of industrial products of constant quantity and quality, sold by domestic producers on the domestic and non-domestic market.

PPI is a Laspeyres type chain index with monthly overlap (December 2021). The PPI is calculated by using the NKD 2007 (based on the NACE Rev. 2) for the following sections of industrial activities: B (Mining and quarrying), C (Manufacturing), D (Electricity, gas, steam and air conditioning supply) and E (Water supply; sewerage, waste management and remediation activities) – only division 36 and by main industrial groupings – GIG 2009 (=MIGs 2009) according to the end-use of products, as follows: Intermediate goods (AI), Energy (AE), Capital goods (BB), Durable consumer goods (CD) and Non-durable consumer goods (CN). December of the previous year has been taken as the base month for price changes.

Weights are based on sales value at the group level taken from the PRODCOM Survey on industrial Production (IND – 21/PRODCOM/G form) for 2021. The data are not seasonally adjusted.

Enterprises and local units, reporting prices on selected products.

The statistical population comprises the observation units - all industrial products/items defined by Nomenclature of industrial products -NIP which are produced by reporting units: enterprises operating in the NACE/CPA classes within industrial sectors B, C, D and E (only division 36) of the NKD 2007 (=NACE Rev.2) or part of enterprises which secondary activities (local units) falls within above described industrial coverage for IPI.

 The whole territory of the Republic of Croatia is covered

The PPI domestic has been calculated since 1962. The present EC harmonised PPI domestic, non-domestic and total datasets on monthly basis are avaliable from 2000 (based on NACE Rev.2).

December of privious year since the Croatian PPI is annually chain-linked Laspeyres type index.

Base period for PPI calculation for 2022 is December 2021 (one-month overlap).

Time series for PPI are available since 2000 based on NACE, Rev. 2. on 2-digits divisions level and sections level as well as on MIGs, 2015=100 and on month by month basis.

Indices

The prices refer to the 15^th day of the reference month.

Legal basis on the national level the Official Statistics Act (Official Gazette, Nos. 25/20) established the responsibility for collecting, processing and dissemination of data. The Croatian Bureau of Statistics is the main producer, disseminator and coordinator of the official statistics system of the Republic of Croatia. The tasks of producing agencies in Croatia were established by the Official Statistics Act (Official Gazette, Nos. 25/20). The producers of official statistics have the right to collect data from all available sources.

Statistical activities have been established by the Programme of Statistical Activities of the Republic of Croatia 2021 - 2027 and the Development Strategy fo Official Statistics of the Republic of Croatia 2021 - 2030.

Legal basis on the european level are the Regulation (EU) of the European Parliament and of the Council No. 2019/2152 and the Commission Regulation (EU) No. 2020/1197.

Nationally, data sharing between the producing agencies is regulated by the Ordinance on the Use of Confidential Statistical Data for each statistics by the individual agreements between individual producing agencies and CBS.

Internationally, PPI are transmitted, in addition to Eurostat, directly to other international organisations like UNE/ECE, OECD and IMF on their request.

The statistical confidentiality of Croatian CBS is regulated by:

• Official Statistics Act, OG, Nos 25/20
• Ordinance on the Access to Confidential Data of the Croatian Bureau of Statistics within the System of Official Statistics (defines conditions of handing over of confidential statistical data of the Croatian Bureau of Statistics to other producers of official statistics in the Republic of Croatia as well as methods of applying the safekeeping measures of the confidential statistical data handed over to the Bureau by other producers of the official statistics in the Republic of Croatia)
• Instruction on the Protection Rules and Methods for the Dissemination of Official Statistics of the Croatian Bureau of Statistics (regulates the rules and methods for ensuring the dissemination of official statistical data within the scope of the Croatian Bureau of Statistics in the form and manner that protect the statistical unit from direct or indirect identification)
• Ordinance on the Conditions and Terms of Access and Use of confidetial Statistical Data of the Croatian Bureau of Statistics for Scientific Purposes (defines conditions and terms of permitting the access to confidential statistical data of the Croatian Bureau of Statistics for scientific purposes)
• Instruction on the Method of Protection of Confidental Statistical Data in the Croatian Bureau of Statistics (regulates procedures and measures for storing and protecting statistical data by applying physical, technical and organizational measures required to ensure statistical data from unauhorised access, alteration, loss or destruction, responsibility implementing measures and protection procedures and other issues relevant to the security of statistical data).

Confidential data are not published. The minimum number of units for which data should be kept confidential, in practice, is less than 3 units (not relevant for PPI)

The Calendar of Statistical Data Issues provides a precise overview of the publications due to be released by the CBS for the entire statistical year, one year in advance. According to the Official Statistics Act, the release date of the Calendar is three months prior to the release date of the first publication of the following year. The release date is usually in October. It is bilingual and published on CBS website in pdf format.

The Calendar of Statistical Data Issues for 2022 is available on the website of Croatian Bureau of Statistics, free of charge. 

CBS publications including first releases are announced in advance and have to be released in accordance with the plan announced in the Calendar of Statistical Data Issues, and be available on the CBS website to all users, precisely at 11 o'clock on the set date. Every departure from the plan disclosed in the Calendar shall be previously announced, an explanation shall be given, and new release date shall be set.

Consequently, all issues of publications including first releases are released on the CBS website simultaneously to all users, and are available both, in Croatian and English language. Users can download the data and read the first release at the same time. No users have prior access to the release data prior to their release on CBS website, precisely at 11 o'clock on the set date.

Monthly (PPI)

 Regular first releases according to the Calendar of Statistical Data Issues, 2022, are dedicated to PPI recent monthly gross series:

Electronic< - First Release No 2.1.1 entitled as Industrial Producers' Price Index, 2022 is available for a fee of charge, bilingual (Croatian and English) on CBS web-site

News releases (both, electronic and hard copy versions) are issued at 11 AM according to the Calendar of Statistical Data Issues, 2022, available for a free of charge, bilingual (Croatian and English) on CBS web-site:

http://www.dzs.hr/Eng/Publication/calendar.htm

Regular electronic and hard copy publications which include PPI, according to Publishing Programme are as follows:

Statistical report as annual publication:  "Short-Term Indicators of industry, 2022 – Industrial Production, Producer Prices and Turnover of Industry" as annual publication with the most detailed and comprehensive PPI results and time series,

CROATIA IN FIGURES – annual publication includes the most important data on economic and social changes in the Republic of Croatia presented in five-year annual series – Chapter 7-Prices includes PPI

STATISTICAL INFORMATION – annual publication contains a summary of annual data for the Republic of Croatia. within table INDICES OF BASIC ECONOMIC INDICATORS include 3-years annual PPI time series (chain linked)

Statistical Year Book of the Republic of Croatia - Chapter 17 "INDUSTRY" includes PPI time series

Data available in STS Database on CBS website

Available upon request only based on the CBS Ordinance on Conditions and Terms of Using Confidential Statistical Data for Scientific Purposes, October 2013, avaiiable on CBS web-site:

CBS Ordinance on Conditions and Terms of Using Confidential Statistical Data for Scientific Purposes, October 2013

Final data are sent to Eurostat to be used in the compilation of the European aggregates and to be released as national data.

A short explanation of the methodology is given in every issue of the First Release: IND-2022-1-1/1 Industrial Producer Price Index, 2022

More thorough methodological descriptions and definitions are given in every issue of the annual Statistical Report as well as in the Statistical Yearbook (for details see also 10.2).

Documentation on procedures applied for quality management and quality assessment developed within TQM framework. Quality database is developed and quality reports for PPI are currently available only internally (on the CBS Intranet).

CBS Quality dedicated web-site:

http://www.dzs.hr/Eng/international/Quality_Report/Quality_Report_Pages/Quality_Report.htm

The quality policy of the CBS is to continuously monitor and improve all statistical processes and products. CBS takes care not only about providers of statistical data but of users also. The CBS, in all statistical value chain - from the collection, processing, production to the dissemination of statistics, takes care about the quality of statistical processes, the final results or products and the level of services provided to its users. Moreover, following the example of the ESS, the CBS has developed a model of the Total Quality Management based on the Code of Practice of European Statistics.

Quality Report

The CBS established tools for quality assurance by creating Quality database within IPA project. Standard template for comprehensive quality reporting has developed based on the ESMS and ESQRS structures. In order to produce a comprehensive quality report in a way that all quality indicators are taken into account, the CBS has prepared a Handbook for Calculating Key Quality Indicators, avaliable on CBS web-site:

Industrial Producer Price Index methodology

CBS focus on quality assurance also by written statement that “Croatian official statistics should be of enough quality and produced in the most efficient way under Official Statistics Act (Official Gazette, No 12/2013 – consolidated text).

PPI is highly relevant for national and international users as well as internally for as (as input to quarterly national accounts). PPI is based on reliable survey data and the level of accuracy is high. PPI calculation is based on recommended international methodology. Publication of results is always punctual, fast and easy assessable. Notes on methodology are clear and comprehensive for users’ needs. PPI is internationally comparable since follows EU and relevant international concept, definitions and classifications. Comparability over time is good in greatest extend and within required length of time series for PPI domestic. Comparability with other statistical domains primarily with PRODCOM is ensured.

International main users: Eurostat, ECB, IMF, UN/ECE, OECD

National main users: Croatian National Bank, Ministry of Economy, Ministry of Finance, other government bodies, Institute of Economic Zagreb (EIZ),

Other users: trade unions, businesses, researchers and students, Media, general public

Internal users (as national accounts)

CBS user satisfaction surveys were conducted in November 2013 and May 2015, with combination of web based interviewing and telephone interviewing. In total, 310 CBS users answered the survey, the largest number of them being media users. Researchers and government bodies use CBS data the longest, and generally, more than half of users in the sample use CBS data longer than 5 years. Most users used CBS data in last month or at least in last half year and about 10% of users use CBS data on daily bases. Generally, CBS data are most frequently used by government bodies and researchers.

Quality Report

The main channel for acquiring CBS data is our website, but also CBS employees, whose help is mostly used by government bodies, economy and researchers. Opinion about CBS website is divided, still about 1/3 of respondents is not satisfied. Dissatisfaction is related to insufficient data bases, available publication formats and layout (structure) of the official CBS website.

In overall, it is evident that main advantage and source of satisfaction are CBS employees, while technical problems are main dissatisfaction reason. Publication format and website are first aspects that should be upgraded, as these aspects significantly influence satisfaction with CBS and can be relatively easy improved.

Time series for PPI are available since 2000 based on NACE Rev.2 on 2-digits divisions’ level and sections level as well as on MIGs, 2015=100 and on month-by-month basis.

Since the response rate for the Monthly Survey on Producers' Prices (IND-3/KPS/M) is about 95% to 99% overall accuracy is good.

There is no sampling error, cut-off survey are using for data collection.

Procedures for unit non-response: Up to 2 % of small-sized enterprises (statistical units) do not fill the monthly questionnaires IND-3/KPS/M even after urging them. Data are imputed manually based on previous month data.

Procedures for item non-response, replacement, other treatments:

• Treatment of missing prices: If temporarily not available, missing prices are carried forward until the product reappears. If permanently not available, missing prices are imputed by using observations from another, similar product.
• Selection of replacement items: If a current product is permanently unavailable, the replacement is done with a comparable product of the same producer or with the same/similar product of another producer.
• Adjustments for quality differences: In the most cases, during the year the adjustment is done by direct comparison method (assuming that there are no significant quality differences between the old and new product). At the end of the year (in December) the annual updating of the product and specification list is used to deal with differences in quality.
• Introducing new products: Annually, at the beginning of a calendar year, according to the Annual Industry Report and additional proposals from producers.
• Seasonal items: If seasonal items are temporarily not available, the last observed price is carried forward until a price can once again be obtained.

Verification of prices: Reporting units verify prices of the products by reporting prices for both the current and the previous month and, if any changes occurred, those changes have to be explained in the questionnaire. In CBS, prices have been checked by checking prices on questionnaires, by data entry and by telephone in cases when the questionnaire is not properly completed.

Timing of price observation: The prices are recorded as transaction prices in effect on the 15th of the reported month. Actual data reporting period for data collection is between 16^th to 26 of the current month (for previous month point of time).

Timing of disemination: First results are available around 12^th in month for previous month’s data, with an exception for January data, which are available with a short delay (but not later than two weeks after the end of the reference month) due to updating sampled units or when classification system has been revised.

All the IPI First Releases for 2022 have been published at 11 o'clock on the day announced in the Calendar of Statistical Data Issues, 2022.

Since Croatian PPI is in compliance with STS requirements it is comparable among Member States

Time series, monthly, for PPI domestic, non domestic and total are available since January 2000 based on NACE Rev.2 on 2-digits division level and sections level as well as on MIGs.

Cross-domain consistency has being achieved with annual PRODCOM survey on industrial production data - where data are being collecting on a wider range of details for about 6 000 products items, according to the Nomenclature of industrial products – NIP for annual production survey. NIP is systematically related to PRODCOM List headings with further national breakdowns since 1995. Collection of annual data is based on NIP versions which are updated annually according to PRODCOM List changes; currently NIP 2021 are using in line with PRODCOM List 2021 of the EU. NIP 2021 (= PRODCOM List 2021) products items are used as weighting coefficient for price products items in PPI based survey. The same survey are being used for updating sample of both, product items and enterprises for PPI based survey in 2022.

Monthly time series for PPI domestic, non-domestic and total are available since January 2000 based on NACE Rev.2 on 2-digits division level and sections level as well as on MIGs.

Starting from 2010 producer's prices are collected on customized questionnaire mostly on electronic form sent by e-mail while starting from January 2011 data collection method has been change to become totally electronic. WEB based e-questionnaires has being introduced instead of both, paper questionnaires sent by post and/or e-questionnaires sent by e-mail. CAWI method applied to reduce both burden on statistics and on respondents. Data collection chain become completely centralised (CBS headquarter is in charge). As a consequence, cost and burden” originated from statistical data collection was significantly reduced for both, respondents and statistics.

Cost for statistics is approximated as follows: The routine costs in Croatia for updating PPI weights each year are approximately 3 persons for 1 month (December) intensively in normal year where no revisions occur due to classifications change. It currently involves four experts manual work in the excel sheets tables approximately 240 hours per expert. In addition, updating the software for data collection, processing and calculations (especially new database construction in SQL) approximately 1 IT persons is needed to work app. 7 days along with experts. Finally, due to updating sample of enterprises/local units) 7 statisticians are involved to contact the enterprise approximately 10 days each year December/January.

Response burden is not very high – respondents need in average 5 to 15 minutes for fulfilling “on-line” questionnaire in 2013 independence of respondent size class (large or SMEs) according to information they provided.

There is no clear revision policy on Croatian statistics level, except that in the case of mistake revised data are marked and explained to users in all publication and resent to Eurostat. In case of revision the same revision policy is applied nationally and in transmissions to Eurostat

The data are published as final and are not subject to any revision, a fact which is noted in the publications.
Major changes in methodology are announced in the First Release: Industrial Producers' Price Index at the time the change is introduced.

If major changes in methodology occurs first there are discussions with the Statistics Advisory Committee for Industry (users and producers) about the proposed new Statistical Standards: these are issued after agreement, with description of major changes or revisions with previous data series.  In addition, the Annual implementation plan (Annual statistical programme) also includes such information discussed first with the Statistical Council. Information of minor methodological changes is provided in Note on methodology which is a part of the first release, all related paper or electronic publications.

MAR/MR =0

A stand-alone monthly survey known as the  Monthly Survey on Industrial Producer Prices (IND-3/KPS/M form) is the main source of information for calculating PPI.

The reporting units included in the IND-3/KPS/MSurvey are selected enterprises (legal entities and tradesmen) that produce selected products as defined in the Nomenclature of Industrial Products – NIP 2021., classified in the NKD 2007. activity sections B Mining and quarrying, C Manufacturing, D Electricity, gas, steam and air conditioning supply and E Water supply; sewerage, waste management and remediation activities (only division 36).

In order to collect data on industrial producer prices on the domestic and non-domestic market, the IND-3/KPS/M Survey for 2022 covers a representative sample of industrial products at the level of covered activity classes of the NKD 2007., that is, all products exceeding 20 million kuna on the domestic market and 15 million kuna on the non-domestic market according to the results of the PRODCOM Survey on Industrial Production (IND 21/ PRODCOM/G form) for 2021, while the selection of enterprises has been done according to their share in the production of selected products, separately for domestic and non-domestic market.

For monitoring of the industrial producer prices on the domestic market, the sample for the IND-3/KPS/M Survey for 2022 covers 2021 item prices within the selected NIP 2021. products in 1191 enterprises (legal entities and tradesmen), while for monitoring of the industrial producer prices of the non-domestic market it covers 1198 item prices within the selected NIP 2021. products in 712 enterprises (legal entities and tradesmen).

 Monthly

Customized web-based questionnaire (CAWI method of data collection) of the Monthly Survey on Industrial Producer Prices (IND-3/KPS/M e-form) is being used for data collection from January 2011. Reporting units are obliged to fulfil the data concerning their production each month via CBS web-site: https://webobrasci.dzs.hr/eSurveyInd/

In order to collect data on industrial producer prices on the domestic and non-domestic market, the IND-3/KPS/M Survey for 2022 covers a representative sample of industrial products at the level of covered activity classes of the NKD 2007., that is, all products exceeding 20 million kuna on the domestic market and 15 million kuna on the non-domestic market according to the results of the PRODCOM Survey on Industrial Production (IND 21/ PRODCOM/G form) for 2021, while the selection of enterprises has been done according to their share in the production of selected products, separately for domestic and non-domestic market.

For monitoring of the industrial producer prices on the domestic market, the sample for the IND-3/KPS/M Survey for 2022 covers 2021 item prices within the selected NIP 2021. products in 1191 enterprises (legal entities and tradesmen), while for monitoring of the industrial producer prices of the non-domestic market it covers 1198 item prices within the selected NIP 2021. products in 712 enterprises (legal entities and tradesmen).

All industrial producer prices are recorded as transaction prices in effect on the 15^th day of a month indicated. Prices at which a producer sells the products at the domestic and/or non-domestic market in the largest quantities to known buyer are recorded. Actual data reporting period for data collection is between 16^th to 26^th of the current month (for previous month point of time).

Types of prices have being collected:

Industrial producer prices on domestic market are either prices at which a producer sells products at the domestic market in the largest quantities, loaded free on rail (truck) at a factory gate at the location of a producer or a price charged to another company by a producer. The selling price is increased for the amount of the compensation obtained by the seller and deducted for the amount of the discount and rebate as well as the value added tax and excises.

Industrial producer prices on non-domestic market are prices at which a producer sells products at the domestic market (outside Croatia) in the largest quantities at the national frontier, FOB (free on board). The selling price is increased for the amount of the compensation obtained by the seller and deducted for the amount of the discount and rebate as well as the value added tax and excises. The reporting units present prices in the national currency – kuna and lipa. The prices expressed in the foreign currency are converted into the national currency on the basis of the mean exchange rate of the Croatian National Bank on the 15^thday of the reference month.

The CBS industrial experts perform all cross-checking, necessary correction after phone call-back procedure for suspicious data, and if it is necessary visiting respondent will be advanced - that is the long-term practice of industrial statistics department to obtain data of good quality.

Validation of prices: Reporting units verify prices of the products by reporting prices for both the current and the previous month and, if any changes occurred, those changes have to be explained in the questionnaire. In CBS, prices have been checked by checking prices on questionnaires, by data entry and by telephone in cases when the questionnaire is not properly completed.

Processing is being verified automatically through established procedures of data treatment and validation each month within production quantities and cumulatively quantities (from the beginning of the year) are confronting and crosschecking.

Cross cutting checks, checks with previous data, investigation of statistical discrepancies in analytical way measuring evaluation on unit level and similar.

 The Croatian PPI is annually chain-linked Laspeyres type index. PPI weights are being updating annually using PRODCOM data (i.e. national more detailed version) since 2000. The base period is December of previous year. However, since the weights for PPI relate to a whole year but the corresponding base period is a single month, the PPI is actually an annually chain-linked Young index.

The Croatian PPI is annually chain-linked Laspeyres type index using a monthly overlap. The chaining period is December of previous year (t-1). The base period is also the December of previous year. Because the weights relate to a whole year but the corresponding base period is a single month (December), the PPI is more precisely an annually chain-linked Young index then Laspeyres. PPI weights are being updating annually using PRODCOM data (i.e. national more detailed version).

The chain linking is performed at each level of aggregation starting from ten-digit product level of PRODCOM based national nomenclature to hierarchical level of NKD 2007 (=NACE Rev.2) classes, groups and divisions as well as on aggregate sub-indices levels (PPI on domestic and non-domestic market) and PPI total.

The total industrial producer price index is composed of two subindices, that is, the industrial producer price index on the domestic market and the industrial producer price index on the non-domestic market.

Elementary price indices for each (elementary) representative product/item of national based PRODCOM nomenclature are being calculated from data on individual prices by dividing individual prices of a current month by individual prices of a base period (December of a previous year).

Higher level indices, that is, aggregate price indices of a classes, groups, divisions and sections of the NKD 2007. (= NACE Rev.2) as well as for MIGs are being calculated by a weighted arithmetic mean from elementary indices according to the modified Laspeyres  formula.

The source of the weights for NACE Rev.2/CPA 2008 higher hieratical levels (4-digits, 3 digits, 2 digits, MIGs ) is production sold volumes and values of annual PRODCOM based survey for both domestic and non-domestic market (so cold relative base structure). The source of the weights for elementary product/item price indices on 10-digit levels are based on production enterprises information on production sold (enterprise-product combination).

Adjustments for quality differences: In the most cases, during the year the adjustment is done by direct comparison method (assuming that there are no significant quality differences between the old and new product). At the end of the year (in December) the annual updating of the product and specification list is used to deal with differences in quality.

PPI has not being seasonally adjusted.

Not available.