Turnover Indices in Other Services

Contact organisation

National Statistical Institute

Contact organisation unit

"Short-term Business Statistics and Statistics of Transport” Department

Contact name

Stela Staykova-Valkova

Contact person function

Chief expert

Contact mail address

2, P. Volov Str.; 1038 Sofia, Bulgaria

Contact email address

[email protected]

Contact phone number

+359 2 9857 137

Contact fax number
Metadata update
Metadata last certified07 April 2020
Metadata last posted07 April 2020
Metadata last update07 April 2020
Statistical presentation
Data description

The turnover index measures the change in the revenues from enterprises sales in current prices. The indices are calculated by fixed base (2015=100). This information is suitable for tracing the current economic development and short-term forecasts. The indices do not measure the actual turnover , they estimate the average turnover change between two time periods.

The index data are presented in the following forms:

  • Unadjusted;
  • Working-day adjusted;
  • Seasonally-adjusted.
Classification system

Classification of Economic Activities  NACE Rev. 2.

Sector coverage

Activieties covered : Sections H, J, parts of M (М69_702, М71, М73 и М74) and parts of N (N78, N79, N80, N812 и N82) of NACE.BG-2008. Turnover indices are calculated by economic activities at divisions and groups (2nd and 3-th digit levels of NACE.BG-2008) and total H, J, M_STS and N_STS.

Statistical concepts and definitions

The turnover includes all revenues from enterprises sales, which are invoiced during the reference period (incl. revenues from sale of row materials and materials, without VAT).

The turnover index measures the change in the revenues from enterprises sales in current prices.

Statistical unit

The surveyed unit is enterprise (Legal unit considered as enterprise).

Statistical population

The total population includes about 165 000 enterprises. The sampling population includes about 46 000 enterprises of which sample of approximately 9 300 units are surveyed. The sample making up 75% of the annual turnover of the enterprises in the sections H, J, M_STS and N_STS.

Reference area

All regions of Bulgaria are covered.

Time coverage

The indices are calculated from the first quarter of 2000 to the last quarter of the reference year.

Base period

Year 2015=100

Unit of measure

Indices (%).

Reference period


Institutional mandate
Legal acts and other agreements

National Legal basis: The Law on Statistics (Article 20) states that all persons that manage or represent legal persons, are obliged to provide the National Statistical Institute and the Bodies of Statistics with reliable data when filling-in forms and questionnaires on surveys included in the National Statistical Programme, for which mandatory participation is provided.

EU Legaslation:

· COUNCIL REGULATION (EC) No 1165/98 of 19 May 1998 concerning short-term statistics;

· REGULATION (EC) No 1158/2005 of the European Parliament and of the Council of 6 July 2005 amending Council Regulation (EC) No 1165/98 concerning short-term statistics;

· COMMISSION REGULATION (EC) No 1503/2006 of 28 September 2006 implementing and amending Council Regulation (EC) No 1165/98 concerning short-term statistics as regards definitions of variables, list of variables and frequency of data compilation;

· REGULATION (EC) No 1893/2006 of the European Parliament and of the Council of 20 December 2006 establishing the statistical classification of economic activities NACE Revision 2 and amending Council Regulation (EEC) No 3037/90 as well as certain EC Regulations on specific statistical domains;

· COMMISSION REGULATION (EC) No 472/2008 of 29 May 2008 implementing Council Regulation (EC) No 1165/98 concerning short-term statistics as regards the first base year to be applied for time series in NACE Revision 2 and, for time series prior to 2009 to be transmitted according to NACE Revision 2, the level of detail, the form, the first reference period, and the reference period.

Data sharing

Selected data in special formats are transmitted quarterly to the Eurostat.

Confidentiality - policy

· The Law on Statistics includes provisions relating to data confidentiality and protection of secrecy, which are in compliance with the EU legislation and standard European practice. In the Law is stated that individual data received and collected at the time of statistical surveys shall be statistical confidentiality and shall be used only for statistical purposes. Individual data, obtained for the purposes of the statistical surveys, shall not be used as evidence to the bodies of the executive powers and the judicial authorities. Requirements, obligations and measures for data protection, as well as fines that can be imposed, are treated in separate chapters, namely Chapter 6 on "Protection of secrecy" and Chapter 9 on "Administrative penal provisions".

· Regulation (EC) No 223/2009 on European statistics (recital 24 and Article 20(4)) of 11 March 2009 (OJ L 87, p. 164), stipulates the need to establish common principles and guidelines ensuring the confidentiality of data used for the production of European statistics and the access to those confidential data with due account for technical developments and the requirements of users in a democratic society.

Confidentiality - data treatment

Article 25 of the Law on Statistics specifies the criteria, according to which certain data cannot be made public or released - individual data, data which could be indirectly identified, as well as aggregations of less than three statistical units and/or when the relative share of one parameter is more than 85% of the total volume of this parameter for all population units.

Data, which according to the Law on statistics are confidential, are not published.

Release policy
Release calendar

The date for publication of statistical information is listed in the Release calendar by dates and by themes. Turnover indices are published 50 days after the end of the quarter.

Release calendar access

The calendar is available on the NSI website: http://www.nsi.bg/en/node/480

User access

The data are published on the NSI website, section Business Statistics in accordance with the Law on Statistics and the European Statistics Code of Practice respecting the professional independence and aimed at objectivity, transparency and equal treatment of all consumers.The data are available in the on-line database INFOSTAT.

Frequency of dissemination


Accessibility and clarity
News release

NSI publishes regular quarterly press release on turnover indices in services 50 days after the end of the reference quarter.



On-line database

A data for the period 2017 - 2019 could be found on the NSI website in section Business statistics: http://www.nsi.bg/en/content/6874/quarterly-data.

The time series has been recalculated according to the new base year and they can be downloaded from INFOSTAT information system: https://infostat.nsi.bg/infostat/pages/module.jsf?x_2=217 



Micro-data access

Not applicable.


Not applicable.

Documentation on methodology

The Methodology of Short-term Business Statistics, Interpretation and guidelines, contains a comprehensive set of recommendations on the compilation of the STS statistics: http://ec.europa.eu/eurostat/web/short-term-business-statistics/methodology

Survey Methodology of turnover indices in services: http://www.nsi.bg/en/node/7884



Quality documentation

Regulation (EC) № 1165/98 and amendment Regulation (EC) № 1158/2005 on Short-term statistics required by the European Commission (Eurostat) regularly (every three years) to report to the European Parliament on the applicability of short-term data, their quality and revisions of the data. In March 2004 was launched a project to capture the quality of short-term indicators. Every year Member States should present to Eurostat detailed information about the quality of a particular short-term indicator, which is part of the Principal European Economic Indicators (PEEIs). Latest Report on the quality of Services turnover index was prepared and submitted to Eurostat in 2010.

Quality management
Quality assurance

The legal framework which regulates the production of data from Short-term business statistics states that statistical data compiled within the EU system must be of satisfactory quality and produced data are comparable between Member States. Verification of data is done through the process of conducting a statistical survey - from respondents, from experts in the regional statistical offices and from national experts in NSI. Identified inaccuracies and errors are removed timely and comparable data of good quality are provided. The quality of statistical information and its production process is ensured by the provisions of the European Statistics Code of Practice. The documentation on quality management is available on the Internet.

Quality assessment

In accordance with European and international standards, instructions are followed in relation to concepts, definitions and methodology.

User needs

Main users of the information are:

  • Eurostat;
  • Representatives of central and local government;
  • Media and organizations, business.
  • Internal users: Directorate „Macroeconomic statistics“.

Quarterly turnover indices measure changes in the turnover of enterprises in services; this information is suitable for monitoring of current economic developments and short-term forecasts.

One of the main requirements of users is the availability of long time series. This applies to all indicators of short-term business statistics. Turnover indices in services are calculated from the first quarter of 2000.

User satisfaction

Not measured


Services turnover indices are calculated and published at all levels of detail that are required by the Regulations concerning STS.

Accuracy and reliability
Overall accuracy

For indices estimation is conducted a representative survey for the enterprises from sections H, J, M_STS and N_STS. The sample is computed annually based on the annual survey on SBS and covers businesses with an annual turnover exceeding 75% of the turnover of each observed activity. The sample is updated throughout the year, each change is recorded in the Register of statistical units.

There are a maximum accuracy and reliability of the data to calculate indices of turnover. Avoiding common errors appear misunderstanding the respondent what information is required or incomplete performance. Most measurement errors are detected and corrected by control logic and arithmetic underlying the information system "Short-term business statistics" (ISSTS – On-line information system for collection, verification and processing of data from short-term business statistics).

Sampling error

Applied sampling method is "stratified random sample" in which first the enterprises stratify by level of activity (2 - or 3-digit codes of NACE.BG-2008) and then at each level in terms of turnover. Also stratified by activity groups are defined by four subsets. From each subset is determined enterprises will fall into the sample through unintentional random props that provides equal opportunities for all businesses to fall or not to fall into the sample for survey. The first subset includes enterprises with the highest turnover of any activity group, which are observed exhaustive. For the second and third subsets is used random sampling. The fourth includes enterprises with negligible or very low turnover, which do not fall in the sample.

Extrapolation of the results to the population is made by using extrapolation coefficients which are based on the turnover of the selected units and total turnover in the particular strata.

The selection of statistical units falling in the sample and sampling errors are computed with SPSS.

Coefficient of variation is used as an indicator on precision. It is computed as a percentage.

Coefficient of variation for fourth quarter of 2019



Coefficient of variation (%)

Transportation, storage and post



Information and communication



Other business services










Non-sampling error

Mistakes made in the processing of the data are detected and removed by set arithmetic and logical controls by ISSTS.

Non-responder enterprises are performed imputation of data depending on the activity and stratum, using extrapolation coefficients.

The overall average response rate is around 90% in terms of the number of enterprises and about 95% when weighted with turnover. It varies significantly, depending on the principle activity and size of the enterprises.

Timeliness and punctuality

Turnover indices in services are released 50 days after the end of the reference quarter.


Regulation concerning STS requires turnover indices in services to be provided to Eurostat 2 months after the end of the reference quarter.

Coherence and comparability
Comparability - geographical

Turnover indices are representative for the whole country; they are not representative by regions of the country. NSI applies methodology, which is in line with international standards. In this sense, the comparability of the indicators across countries can be considered as very good.


Comparability - over time

The quarter indices are presented as time series from first quarter of 2000 according to NACE.BG-2008 at base year 2015 which are published in the site of NSI and on-line system INFOSTAT.


Coherence - cross domain

Turnover indexes are compared with turnover indexes calculated on the base of annual Structural business statistics (SBS) survey. Also SBS is the source of weights for calculation the STS indicators. Data received from SBS and those receives from STS are coherent.

Coherence - internal

Not applicable.

Cost and burden

Since the beginning of 2012 NSI have started an online information system for data collection, data editing and data processing of STS information. Information system “Short-term statistics” provides more efficient way of collecting data from enterprises. This new system save recourses, reduce the burden of the reporting units and the quality of short term indicators is improved.

Data revision
Data revision - policy

There are always a difference between STS data of the enterprises and their annual accounts. At the beginning of each year the indexes for the previous year are reconciled on the basis of the comprehensive annual data from SBS.

Data revision - practice

Minor changes are made at the time when the revision is introduced and they are marked in footnotes in the relevant published tables.

Statistical processing
Source data

Information for the indices calculation is on the base of monthly survey "Sales in industry, construction, trade and services".

Turnover includes all net revenues from enterprises sales of products, goods and services which are invoiced during the reference year also includes revenues from sale of raw materials and materials ( incl. excise without VAT).

Frequency of data collection


Data collection

Sampling survey. For indices estimation is conducted a representative survey for the enterprises with main activity transport and communication and in the sample are included enterprises with annual turnover over 75% of the total turnover in the sector.

Data collection media:

  • Online through Information system “Short-term business statistics”
  • Paper questionnaire. The questionnaires are sent out to the respondents and collected by regional statistical offices, where the information is entered into Information system “Short-term business statistics”.

To reduce non-response Information system “Short-term business statistics” has functionality to send an informative and a reminder letters to respondents.


Data validation

Validation of data in the report:

When recording the data, the system carries out obligatory and recommended controls according to set with validation rules.

The system carries out the statutory and warning controls. In case there are errors, it displays a warning dialog error in the report. The system does not allow completion of the report until they have corrected these errors by statutory controls.

Validation of the output data:

Output data is verified at group level with regard to the previous quarter, the same quarter of the previous year and also with regard to extreme values, if necessary data is validated at the level of statistical units

Data compilation

At the lower level of aggregation (2-nd digit level of NACE.BG-2008) indices calculation is made on the bases of direct comparison of the data from the current quarter and data on the average quarter turnover value in the base year.

At higher level of aggregation indexes are calculated as weighted average - indices at lower levels are weighted with turnover structure.


Turnover indexes are published as:

  • Unadjusted time series;
  • Working day adjusted time series;
  • Seasonally adjusted time series.

The software used for seasonal and working day adjustment is JDEMETRA+ (TRAMO-SEATS).

The purpose of working day adjustment is to check and eliminate the significance of the calendar effects as the results from the difference in the number of working days and holidays in the national calendar.

The purpose of seasonal adjustment is to remove ordinary seasonal variation. The series of data are checked for outliers of different types and typical calendar effects on the dynamics of a given indicator. Usually seasonal fluctuations are those changes that are repeated seasonally each year.

Time series the indices of building construction and civil engineering are seasonal and working day adjusted, and time series of the indices of construction - total obtained by applying the indirect method.

Revisions to seasonally adjusted data are published in accordance with accepted revision policy and release calendar that is aligned with the revision policy and the revision calendar for the unadjusted data.

Metadata Structure Definition in SDMX 2.1: ESMS_MSD+BNSI+2.0+SDMX.2.1.xml
Metadata Structure Definition in SDMX 2.0: ESMS_MSD+BNSI+2.0+SDMX.2.0.xml
  • Seasonally unadjusted
  • Seasonally adjusted
  • Working day adjusted
  • Friday, 21 August 2015 - 11:00
    According to the preliminary data for the second quarter of 2015 the total turnover index in section ‘Transportation, storage and post’, calculated on the basis of seasonally adjusted data was 0.2% higher than the previous quarter. In section ‘Information and communication’ the turnover index decreased by 0.4%.
  • Thursday, 21 May 2015 - 11:00

    According to the preliminary data for the first quarter of 2015 the total turnover index in section ‘Transportation, storage and post’, calculated on the basis of seasonally adjusted data increased by 5.2% as compared to the fourth quarter of 2014. In section ‘Information and communication’ the turnover index grew by 2.8%.

  • Monday, 23 February 2015 - 11:00

    According to the preliminary data in the fourth quarter of 2014 the total turnover index in section ‘Transportation, storage and post’, calculated on the basis of seasonally adjusted data, increased by 3.8% than the previous quarter, while in section ‘Information and communication’ - by 3.3%.

  • Friday, 21 November 2014 - 11:00

    According to the preliminary data in the third quarter of 2014 the total turnover index for section ‘Transportation, storage and post’, calculated on the basis of seasonally adjusted data, decreased by 2.7% than the previous quarter, while in section ‘Information and communication’ - by 1.2%.

  • Thursday, 21 August 2014 - 11:00

    According to the preliminary data in the second quarter of 2014 the total turnover index for section “Transportation, storage and post”, calculated on the basis of seasonally adjusted data, was 1.7% higher than the previous quarter. In section „Information and communication” the turnover index decreased by 1.4%.

  • Wednesday, 21 May 2014 - 11:00

    According to preliminary data from the first quarter of 2014 the total turnover index for section “Transportation, storage and post”, calculated on the basis of seasonally adjusted data was 20.9% higher than the previous quarter. In section „Information and communication” the turnover index increased by 3.8%.