I see where you’re coming from, but using a fire arm in self defense is not always involving the firearm being discharged. Most of the time just as soon as the defender brandishes the firearm it’s enough to scare off the predator/robber/assaulter/road rager etc.

So that’s where we struggle with the numbers. They were over several years able to pull data that could be backed up by media and police, but if the guy ran off, sometimes someone may not report it. Also pretty sure the self defense claims can be of livestock so if a mountain lion was threatening you or your livestock it’s also part of self defense using a firearm.

Never hurts to click an article, they often provide the context necessary to make judgement.