I periodically lose points because a "user was removed." I've often thought, "Wait...what? The questions I answered recently were all benign, and there's no way that the OP would have gone ballistic, started spewing venom, and had their account deleted" (although I recognize that there are other reasons for removal as well).
I now realize that it could be that the OP may have simply asked a question or two, gotten answers, and decided to remove their account for some reason, that is, there might have been a self-removal rather than a moderator-removal. That seems OK, and I can live with the reputation loss, of course.
But it made me wonder: Can someone with better search-abilities or permissions tell, for some recent month like September, what fraction of "user removed" events (in MSE) were self-removals and what fraction were moderator removals?
What I'd really like, of course, is to figure out how to avoid spending time answering questions that will soon go away, but that's probably asking too much.