Beansbeans - Thanks for that link, if I read it correctly, german sheppards have attacked more than pitbull?
While it is true that the number of attacks by german shepherds is higher (there are a lot more german shepherds after all), only 0.2% of german shepherds were reported to have attacked, but 1.0% of pitbulls were reported. These stats are for the purebreeds. For crossbreeds, 0.1% of german shepherd crosses and 1.5% of pitbull crosses were reported.

What I found concerning in those stats is that 80% of attacks occurred while the dog was allegedly under control.