Quoted from Minneapolispin:Agree -the 90's games would seem to be a bit higher.
I don't know, think about who was buying the games back then. There were a lot of large chain arcades, and if you just look at the policies of one of those, Chuckie Cheese, which was to destroy all games once they were done with them. That could account for a pretty large divot into the percentage of games still existing.