For the intercensus periods data on size and structure of population are calculated for each gmina on the basis of results of completed census; then each year data are computed by balance method according to following schema: balance of population for gmina (for the beginning of year or quarter) + live births – deaths + registration of arrival for permanent stay (from other gminas or from abroad) - registration of departure for permanent stay (from other gminas or from abroad) + registration of arrival for a temporary stay (for 3 months and over) - registration of departure for a temporary stay (for 3 months and over) +(-) modification of population size caused by changes in the administrative division of a country, which are reflected in Regulation of Council of Ministers on establishing the boundaries of certain gminas and cities and granting city status to certain localities = balance of population for gmina (for the end of year or quarter).
Balance of population according to above-mentioned method is compiled since 2010. Until 2009 balance of population was compiled for two categories of population: 1. de facto population (population actually residing/leaving in a given administrative unit - i.e. gmina), 2. de jure population (population registered for permanent stay in a given administrative unit - i.e. gmina). Difference between these two categories of residence is made by balance (+/-) of population registered for a temporary stay for 3 months and over (until 2005 - for 2 months and over). Since 2010 the balance of population was prepared for one category (formerly called "de facto population").
The data presented in the Local Data Bank (for communes and in total for voivodeships and Poland in total) for the years 1995-1998 and as of June 30, 1999 - constituting a balance prepared on the basis of the results of the Census of 1988 - are only of historical importance. Data on de jure population (population registered for permanent residence) from June 30, 1999 to December 31, 2009 were compiled on the basis of the results of the 2002 Census (de jure population was used only for the purpose of calculating demographic indicators).
Since 2010, the results of the National Population and Housing Census 2011 have been the basis for the balance of the population size and structure. As the population balance for persons registered for permanent stay is no longer prepared, the methodology for calculating all demographic indicators has been altered, particular facts related to demography and migration have been presented in relation the population formerly called "de facto population". Balance data for permanent and de facto population as well as demographic indicators for 2010 that were based on the 2002 National Census, present only historical value and are available in the archives.
The 2010 population balance data have been prepared according to the administrative division of the country as of 1 January 2011, however due to the specificity of the Local Data Bank they have been recalculated according to the administrative division of the country as of 1 January 2010 (the changes that do not affect the codes or the names of territorial division units have not been taken into account). This has resulted in a difference relative to the data published in the Statistics Poland reports. For comparison, the information on five gminas (rural in 2010 and urban-rural in 2011) according to the administrative division of the country as of 1 January 2011 for year 2010 is available in this report download file.
From 2020, the base for the balance of the size and structure of the population are the results of the National Census of Population and Housing 2021. The results of the Census 2021 showed the population of Poland by approx. 173 thousands smaller in relation to the conducted population balances. Based on the results of the Census 2021, data on the state and structure of the population for the years 2020 and 2021 have been recalculated. Data on the population and indicators for the above years, which were based on the Census 2011 data present only historical value and are available in the archives.
Please be advised that the tables containing the age structure of the population may contain negative values. This situation results from the population balance methodology, which uses data on the facts of vital statistics and migration flows based on administrative sources, while the census is based on information about the actual place of residence. The occurrence of negative values in the population balance is a consequence of incorrect, i.e. inconsistent with the facts, declarations in the census and incorrect interpretation of the definition of the place of residence by respondents, as well as neglection of the obligation to register. Children in school age were indicated in the Census with a different address of residence, e.g. the gmina where they study, instead of the gmina of permanent residence. In small gminas where the number of persons of a given age during the census was small, the fact of deregistration after the census with a different address of residence - than the one indicated in the census - may result in the appearance of a negative population number.
The method and the data sources used in the development of the population balance and their assessment have been discussed in detail in methodological reports Vital statistic. Balances of population and Migrations of the population. Aspects of migrations surveys used in