Apostrophes for possessive, not plural.
Mods please lock this thread.
Grape,
LOL, when I first typed the subject line I did not have the apostrophe.  Then I thought that it didn't look right, so I added the apostrophe.  Afterall, these men all 
possess the title of Mr. Olympia.  At any rate, I stand corrected!   

  (Fyi, math was my best subject in high school and college, not grammar.)