Synthetic index of fertility and average age to motherhood in the Basque Country by birth range, historical territory and region, according to year.

The study of the demographic phenomena Mortality, Bridality, Fertility and Migration requires developing a series of indicators and synthetic indices, and this is the objective of the statistical operation Demographic Indicators (ID) in its annual scope. The Synthetic Fertility Index according to the average age at motherhood, the Synthetic Nuptiality Index according to the average age to the nuptiality, or the life expectancy at birth are the result of this statistical synthesis operation; the results are disseminated by sex and region within the A.C. of the Basque Country.