Even that figure is going to be generous to Derby, as the attendances they declare are much less than what is actually in the stadium (for example, someone posted a picture from their match the other week in this thread; the stadium looked about a third empty but Derby claimed a 29k+ attendance).Ben HD did a ranking of how full the stadiums are and Pride(less) Park was 84% full on average over the season while City Ground was in the top ten with 99% filled on average. Newcastle topped it.
I dunno how much scope you want to put in that.