Yeah I think this is it. I played a few times and at one point I was a woman and the average number of children women had was 6 or 7 primarily because most children died pretty early at that time.
Was the story or stats true? I dunno. But it makes sense, and I poked around some of the sources and it was just fun to play with.
For example my draw died as a newborn (allegedly 50% died before 5), which made me think how many humans never really got to experience life.