The FBI tracks Law Enforcement Officers Killed and Assaulted (LEOKA)[1]. There are around 540,000 police officers in the US, and about 58,000 recorded assault. Now, there are lies, damn lies, and statistics. Some of those assaults are undoubtedly some Kelly Thomas type BS where the cops beat the crap out of a guy and got blood on their uniforms and counted it as assault. There are also likely assaults that don't get listed/reported. E.g. a man who just murdered someone is running from the cops, car chase ensues. 10+ cop cars behind the suspect, who starts shooting at officers. This did not get recorded as 10 assaults, though 10 cops were shot at.
Also keep in mind that these statistics are of all reporting agencies. Every Mayberry town with 100 citizens, 1 sheriff, and 1 deputy. Every command staff and supervisor who are effectively just managers with a badge. The cops who do entirely admin work and don't wear their vest anymore. The High Tech Crimes guys who don't respond to calls, but do computer forensic analysis in pedophile cases. These are all less likely to be assaulted than the cop doing a solo patrol, responding to calls.
_____ [1]1https://ucr.fbi.gov/leoka