There are so many factors here that would change things.. And change the average size. Because In a completely unbiased survey of average penis size, the selection would have to be random, because lets face it, (as said before) no guy with a tiny penis will want to be part of it.
Also, no offense to any one, but guys with below average size would be less likely to be confident and have sex with many girls.. So lets say this factors out <4” (just threw that figure in there), that means that the average (what they consider to be average) would be greatly affected, considering the sizes would be normally distributed (bell curve).
We’re really fighting a losing battle here. Because you may be average->above-average size, but be considered small. I say just PE until we’re something above 7” or find a chick who doesn’t sleep around or doesn’t care about the size of your unit.