Differentiation of the Population by Age and Voivodships in Poland, 1991-2010

From two decades we have observed changing of demographic processes (and these processes were not similar by voivodships) which have lead to changed of structure of the population by age. Purpose of the article is a description of it, extract the similar regions and assessment of the regions structures of the population to the progressive pyramid of age. This approach will allow to assessment of the spatial dynamics of the process of ageing of the population