It all depends on which blocks are released in your area.
I was going to guess you lived in or around Michigan. Here we're getting E-C, F-A, and G-A 2013 notes, which matched up fairly well with your stats. Then I saw the 4 L 2013s and we don't have any of those around here.
I'm finding that most of the $1 bills in circulation here tend not to leave. Even the 2006 and 2009 notes floating around are usually from blocks that were originally released here. I guess not many people drive through Michigan, so it kinda becomes a suckerhole for notes.