From 2020, the results of the National Population and Housing Census 2021 have been the basis for the population balance and structure. Therefore, the data and indicators relating to the size and structure of the population (sex and age groups) from 2020 have been recalculated in accordance with the balance prepared on the basis of the results of the Census 2021. Balance of size and structure of the population in gminas was prepared on the basis of the National Population Censuses including changes connected with vital statistics (births and deaths) and migration of the population (for permanent residence and for temporary stay) and changes caused by administrative changes. The data on population in localities based on PESEL register. The data on registered marriages, births and deaths based on the reports of civil status offices. The data on divorces and separations based on the reports of courts. The data on internal and international migration for permanent residence are obtained from the Ministry of the Interior and Administration. Population projection based the results of survey conducted by the Statistics Poland.