Average penis size for a 14 year old?

I'm 14.. I'm a little worried about my penis size.. A few friends claim to be like 7-9 inches.. Idk if they're tellin the truth or not.. Another friend said she saw a pic of a guys penis and said it was big.. I dnt rlly know what "big" means -_- so anyways.. I'm just under 6 inches erect... Soo am I small,average, or big for my age? :O