The most commonly used measures of current fertility are the total fertility rate (TFR) and its component age-specific fertility rates (ASFRs). The TFR is an estimate of the average number of births a woman would have at the end of her reproductive years if she bears children at the prevailing age-specific fertility rates throughout her childbearing years (age 15-49). The ASFRs are defined in terms of the number of live births among women in a particular age group divided by the number of woman-years in that age group during the specific period. Figure presents trends in.
