There's always the question : Is it bone press top side or down side or insertable lenght....
I mean, for most peoples there is a 1" difference between "bone press down side" and "insertable length".
So just by mesuring differently you gain 1"
Most of the poll stat in the media are "insertable lenght" and most of the poll stat made in PE forum are "bone press top side" and most of the claim are made by the "bone press down side".
In the end, PE are self related, you start with a mesurement and you compare with that mesurement.
Now for the lenght in general, It really does'nt matter, a woman can have orgasm with a insertion of a finger. It mostly the friction that count and how you play with it.
Comparing yourself with others is pointless, You do PE for the esthetic and for yourself and you compare your grow with your own stat.
Big is really a abstraction thing. But if you really need to compare. Physically speaking. In general north american woman can take up to 8" insertable lenght before touching the cervix, without hurthing them. So Big would be 7".