Question about cited study around dog aggression

I completed the course based on safety recently and was discussing the information regarding dog breed aggression with some friends that I had learned. Could you tell me what study this is referring to?

“Dog Aggression by Breed
The likelihood that a dog will become aggressive varies both with breed and with individual dogs. A study of more than 2,200 dog attacks that caused bodily harm was compiled over 17 years (and excluded trained police/guard dogs) and shows that most breeds inflicted fewer than five attacks.”