I’m really surprised that number is so low, the difference between a normal psychopath and successful upper level manager is the money they are paid to do it…
I go back 50 years, and, yes, there were. During the 50s and 60s especially, he was more of a jokester. No homicidal mania once Frederick Wertham came along, and I think most portrayals of him prior to that made him more diabolical than psychopathic: when he killed, it was usually part of some plan (he would have gotten away with it, too, if it wasn’t for that meddling Batman).
I posted about this a long time ago, I think psychopaths make for boring characters, because their evil stems from a pathology. There is no “there” there, they are missing an essential element of humanity. It is very good fodder for lazy writers. I’m thinking of all the villains of the weeks in series like CSI and L&O and all the others, who do horrible things so detectives will have work to do. They always kill one or two victims early on so the audience knows what kind of jeopardy the final victim, who will be saved, is in. By the numbers, and so boring.