The Historical Series section includes population figures from 1900 taken from censuses and registers. The series consists of national data by Autonomous Community, as well as provincial and municipal data and is broken down into three parts, as the population groups considered in each period are not homogenous.
In the 1900-1991 period, the data refer to the de facto population, are ten-yearly and come from each year's population census.
For the 1986-1995 period, the data correspond to the legal population, are annual and come from the register updates for 1986 and 1991 (official figures referring to 1st April and 1st March) and the register corrections for the remaining years (referring to 1st January).
In 1996, the register regulations were modified and a new continuous and computerised management system was set up for municipal registers based on the coordination of all of these by the INE. By virtue of this regulation, the latest register update was carried out in 1996 referring to 1st May, the starting point for a new register management system. The first revision in accordance with the new system was undertaken on 1st January 1998. The distinction between de facto and legal populations is removed.
Other available information offers data compiled and transcribed from census publications. On the one hand, this includes breakdowns by sex and age, with provincial details for censuses since 1900. On the other hand, there is a catalogue of all municipalities where censuses have been taken in Spain since 1842 up until the 2001 census, specifying the inhabitants registered in each census and the alterations made in terms of: name, territory and the creation and removal of entries if necessary.
Eurostat's website is the information source for European data where further information can be found through the theme Population and social conditions.