Huh. Usually my first kid doesn't come of age before I'm, like, 30something, which still means they aged 20 years in 10 years. Curious. I never looked at that before, I think I'll have to eye it.
Though I know that Brad stated at one point that the time per turn is intended to be meaningless, and that your kids come of age in X turns, and you can apply whatever timeframe you want to the turn schedule based on your own preference, and that that is why they only list what turn number you are on instead of what year. They meant for it to be abstract.