By that measure, Hearts and Hibs have done just as badly as us (Hearts slightly better, Hibs slightly worse).
Dundee Utd on the other hand, are the most successful relatively by reaching our goal returns on half the revenue, presuming we ignore the fact they were relegated during that time period. Twice.
*not a dig incidentally, just a comment on the fickleness of statistics. I do agree we are generally punching well below our weight in relation to how much we spend at present.