The OP wants things that were played the most in the last 12 months. MB doesn't know how many times something was played in the last 12 months, only when it was most recently played.
EDIT: Hmmm...Last.fm does. If you use Last.fm, you could generate a static playlist by right clicking any track, going to Last.fm Playlist->Library Top Tracks->Last Year. But you'd have to do this fresh each time you wanted a new one - no way to make an auto playlist, and I noticed that if you have multiple versions of songs in your library it sometimes does not choose the one that you actually listened to the most (some in the playlist had 0 play count when I tried).
A smile is happiness you'll find right under your nose.