Do you understand the difference between causation and correlation? Only anecdotal evidence (and that by rather iffy sources) links pornography to any of these crimes. If the crimes in question would have dropped regardless of the increase in porn consumption, then porn has nothing to do with these crimes, does it? I wonder if a study would show that increased porn use leads to a decrease in sexual misconduct (the partakers being too tired to actually act, possibly). Hey, the latter has as much validity as your claims, and the evidence appears to back it up.
But hey, don't let facts get in the way of your holy crusade or anything.
We do not know how much more it would have dropped had porn not increased.
I'll make you a deal -- you don't call me a holy crusader and I won't call you a drooling pervert. OK?