Remember when dobermans were such vicious dogs? You don't hear about them anymore, do you? Nope - because they aren't popular anymore.. the more pit bulls, rotties or any breed that are bred & purchased the more they end up in the statistics.
Of course there are more reported bites from them... there are more of them out there because of stupid inexperienced owners who have to have the breed of dog thats "cool".
It's not about statistics... it's about stupidity.