Who knows? If you average ONS's into the stats, they become totally meaningless! Before you can make any statements, you'd need to define "affair". Then you'd have to get people to be honest. Ok, these are people that have had, or are having affairs! So, well, uh, ok, like that's going to happen!
So, no one knows, as far as I can tell. There might be some guesses, some might even be good guesses, but each one is unique, and trying to generalize is probably a waste of perfectly good brain cells!
