If Prof visited a popular target, then how comes no one knows who the Ambusher is? A popular target should get more than 1 visitor. So I still think it was not a popular target. But talking about this will get us nowhere lol. Let's just leave it.
Specifically in ToS?
In one of the previous games, there were 16 players. 3 mafia. 2 harmful indie and 1 semi harmful and 1 non-harmful iirc. So it should be close to 50%.