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) +(-) modification of population size caused by changes in the administrative division of a country=balance of population for gmina (for the end of year or quarter). Balance of population according to above-mentioned method is compiled until 2009 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").
Attention. The results of Census 2002 showed the number of Polish population of about 392 thous. smaller in relation to the population balances conducted. To bridge this gap data on population data for 1989-1999 have been recalculated taking into account the results of Census 2002. Estimate covers only nationwide data broken down by urban and rural areas (by sex and age groups), and demographic indicators - such data have become the official information on the number and structure of the population for these years (data for voivodships and gminas not had been overestimated). Therefore, the data presented (for gminas and globally for voivodships and the Polish total) for the years 1995-1998 and as at June 30 1999 - acting the balance developed on the basis of Census 1988 - have only historical meaning. However data for 1999 as of June, 30 de jure population (population registered for permanent residence) - was prepared based on the results of Census 2002 (data only for calculating demographic rates). Since 1999 to 2009 by territorial units as of 31 of December - data are based on the results of Census 2002. Since 1999 to 2009 by territorial units as of 31 of December - data are based on the results of the Census 2002.
Since 2010, the results of the National Population and Housing Census 2011 have been the basis for the population balance and structure. As the population balance for persons registered for permanent stay is no longer prepared, the methodology for calculating all demographic indices 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 indices for 2010 that were based on the 2002 National Census, present only historical value are available in the archives.
The 2010 population balance data have been prepared according to the administrative division of the country as at 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 at 1 January 2010 (the changes that do not affect the indices 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 Central Statistical Office reports. For comparison, the information on five gminas (rural in 2010 and municipal-rural in 2011) according to the administrative division of the country as at l January 2011 for year 2010 is available in this report download file.