I doubt there is a truly accurate number as many dogs have been mistaken for pit bulls when they are not. I saw a video of a white boxer tasered because the police officer assumed it was a pit bull. The dog was barking but was not being aggressive.
You need to ask yourself how many people or kids are killed by dogs. Pitbulls get a bad rap. I have one and he is as sweet as can be. Another thing is that you do not leave kids and dogs alone no matter the breed so the parents are the dummies and should get charged. And who ever came up with that number 45 is a complete moron. Get your facts straight hoe.