That really depends on what you classify as “violent”. There are a lot of crimes labeled “violent” that don’t include direct physical harm to another person. Eg burglary is labeled as “violent” many places when the actual act was “smashed a window, grabbed a TV and ran away”. Drug manufacturing is also typically considered “violent” even without any kind of assault/murder/turf war/etc.

The numbers I saw said 47% of inmates had a violent crime under federal or state classifications.