There are some good websites with data that goes back up to 30 years on one site. I was surprised that of the different breeds, German Shepherds, Huskies, and Boxers are in the top 5 for number of attacks and fatalities over the past 30+ years. Huskies and German Shepherds I can see a little, but I always thought Boxers where goofy dogs that like to play, but not aggressive.

But the interesting bit I found, is the Pit Bulls have an overwhelming majority of the human deaths. From 2005 to 2016 they were responsible for 65% of the human deaths related to dog attacks. Now, the overall number is small and you are probably more likely to get hit by lightning than face a deadly dog attack. However, the numbers definitely show that of the many dog breeds out there, Pit Bulls have a much higher tendency to attack and hurt people. The numbers don't provide any data to look at a link between causation and the attacks, but the raw data shows that they are a more dangerous breed. Below are a few links to the sites I am referencing.

http://dogs.petbreeds.com/stories/4046/dog-breeds-attack#35-pit-bull

http://www.dogsbite.org/dog-bite-statistics-fatalities.php

https://dogbitelaw.com/dog-bite-statistics/all-dog-bite-statistics
-This site has good data and talks about how overall, dog attacks are rising. Give credence to what other here have alluded too, and that is dog attacks may be closely correlated to owner treatment. More dumb/bad dog owners will lead to an increase in attacks. If you look at our society in general, the link makes some sense.