On average how long does it take for the average male to have there facial hair fully come in?

Yeah as mentioned it really depends on each individual guy; for me i started getting facial hair at around the age of 17; then i was able to grow a full beard by around the age of 19 or 20.On average how long does it take for the average male to have there facial hair fully come in?
It really depends on the individual. I've been able to get a thick goatee and thick sideburns since I was 16, I'm 19 now, and yet still can't get a full chin-strap style going. Where as my brother who is 4 years older than me can't grow anything. Other guys in my dorm who participated in no-shave november had full beards after a week and have apparently been able to do so since the middle of high school. If i had to give you a mean number, I would say somewhere in the low twenties, but I would say men vary so differently in this aspect that any one number is not sufficient.On average how long does it take for the average male to have there facial hair fully come in?
im not sure , but i would like to know this to.