I wonder what percentage of the population plays with guns.
Guy's like ER and I were taught to respect the lethality of guns and so was every shooter I know. I was once told "You treat it like handling a rattlesnake" Would anyone in their right mind turn a 9 year old into a snake handler.
By the way, it can't be known but you can estimate the number of rounds sold annually in the US could be somewhere around 300 million. There must be some sane and responsible gun owners out there.