It seems people don't understand that 'a pitbull' is not breed specific.
It's a slang term that generalizes a group of many many different types of dogs together. Of course those statistics are going to sky rocket when you account for a handful of different breeds grouped together.
"Pitbull (disambiguation)
From Wikipedia, the free encyclopedia
Pitbull or Pit bull is any of several breeds of dog in the molosser breed group.
Pitbull may also refer to:
In dog breeds:
American Pit Bull Terrier
American Staffordshire Terrier
Staffordshire Bull Terrier"
SOURCE:
http://en.wikipedia.org/wiki/Pitbull_(disambiguation)