This is caused by the baby boom generation of the 1960s settling down and having families of their own. BNC
Thereafter, the ageing of the post-war baby boom generation becomes apparent, and by 2031 over one fifth of the population is expected to be aged 65+. BNC
The great increase in the popularity of marriage and the baby boom which it partly caused accompanied the post-war economic growth of the 1950s. BNC