The total fertility rate is the number of children that would be born to each woman at the end of her childbearing years if the likelihood of her giving birth to children at each age was the currently prevailing age-specific fertility rates. It is computed by summing up the age-specific fertility rates defined over fiveyearly intervals. Assuming no net migration and unchanged mortality, total fertility rate of 2.1 children per woman (“replacement”) ensures broad population stability. Data typically come from civil population registers or other administrative records. These are harmonised according to United Nations and Eurostat recommendations. The exception is Turkey, where fertility data are survey-based.