Wikipedia: "It may take several generations for a change in the total fertility rate to be reflected in birth rate, because the age distribution must reach equi

Wikipedia: "It may take several generations for a change in the total fertility rate to be reflected in birth rate, because the age distribution must reach equilibrium. For example, a population that has recently dropped below replacement-level fertility will continue to grow, because the recent high fertility produced large numbers of young couples, who would now be in their childbearing years." See also: https://en.wikipedia.org/wiki/Population_momentum https://en.wikipedia.org/wiki/Population_momentum