SOLUTION TO THE PUZZLE

The correct answer is 72.  Oh God, you are going to kill me.  Several New Yorkers got it right.  This is actually an old high school nerd joke.  They are the stops on the Northbound IRT subway line in Manhattan.  Congratulations to Gerald Dworkin, Andrew Blais, JCE, and M.  Maybe I should stick to commenting on the passing scene or writing lengthy tutorials.  My profound apologies to anyone who spent more than thirty seconds on it.