Where did you get that stat? Are they "Official People's Republic Numbers"? Are you saying that Chinese families of child producing age have an average of 4-5 kids because that's BS and you know it. If "One Child" wasn't causing the population to implode then why did China relax it recently?
Population in China in the 1970s was around 900 Million, today its about 1.3 BILLION.
https://en.wikipedia.org/wiki/Demographics_of_China#/media/File:ChinaDemography.svg