I'm not roped in at all, nor do I succumb to prejudice.
The statistics are all over the web..
Dog Attack Deaths and Maimings, U.S. & Canada, September 1982 to December 31, 2014
By compiling U.S. and Canadian press accounts between 1982 and 2014, Merritt Clifton, editor of Animals 24-7, shows the dog breeds most responsible for disfiguring injuries and deaths.
The combination of molosser breeds, including pit bulls, rottweilers, presa canarios, cane corsos, mastiffs, dogo argentinos, fila brasieros, sharpeis, boxers, and their mixes, inflict:
86% of attacks that induce bodily harm
81% of attacks to children
89% of attack to adults
76% of attacks that result in fatalities
86% that result in maiming
Embody 9.2%+ of the total dog population
Those statistics show that the dogs listed are powerful and capable of inflicting serious injury or death. They are based on reports of serious injury and/or death, not total bite occurrences, the stats are not all inclusive. If a toy fox terrier nips my ankle I'm not likely to call the police for a report nor am I likely to be maimed. They do not show that these dogs are more prone to attack.
If we're going to take a serious look at the tendency to bite we'd probably better put hamsters, guinea pigs and gerbils at the top of the list.