Projections of the population by age and sex are prepared by using the components method, which requires that explicit assumptions be made about future levels and trends of fertility, mortality and international migration.
按年龄和性别分列的人口预测采用的是组合方法，这种方法需要对今后的生育率、死亡率和国际移徙水平与趋势作出明确的假定。