I saw a question on Reddit earlier today that intrigued me...has Iron Maiden ever not played the song Iron Maiden? Setlist.fm lists about 2,500 concerts for the band and indicates that the song has been played about 2,300 times. However, there are tons of pre-1980 shows that have no set list, so that accounts for most of the non-plays (and set lists from those days are notoriously unreliable - especially for club bands, which is what Maiden was in the '70s). I'm guessing the answer is, ultimately, unknowable, but maybe Steve has said something about it in a bio that I've never read.