I've seen way too many wof's in my area alone for there to only be 700 of them.
I don't think ghost busters will ever touch the number of TSPP and pirates out there.
Those were two games that chuck e cheese bought along with alot of operators in my area.
AC/DC may have gotten close because everyone loves the rules. I can think of a few on route near me.
Maybe it's a combination of on route and in collections but I see way more pirates and simpsons than any new stern game.