Only 'fifteen' (of them) showed up on time.
Their boat finished 'fifteenth'.
one 'fifteenth' of the total
(..) You don't know what you're doing! - Straighten her now! You don't know what you're doing! Model citizen. You just missed him. He left fifteen minutes ago. I think he said he was going to the Galleria. - Yeah. The Galleria? I'll get some quarters. I'll be back, alright? (..)1991 Terminator 2: Judgment Day