have you got the "litle red book"?
no, not chairman mao's book
kids nowadays come with a red book and there are graphs on there to show you what "average" is plus and minus 50% of the population

if i get a chance i'll sho you when i get home but if anyone else has one they can probably list the heights (it goes all the way up to 20 year olds so by their reckoning, junior will be a stumpy little 5 foot 8