The smallest portion of the 1638 ratings the ESRB doled out last year belongs to EC which, safe to say, few reading this site ever play. Early Childhood got 1 per cent of the ratings. E accounts for 55 per cent, followed by T at 21 per cent and E10+ at 18 per cent.
Not in this tally, of course, is the dreaded AO, which renders a title effectively unpublishable in North America. Just 24 games have been rated AO in the 17 year history of the classification, one of the original five ratings. The most recent AO-rated game was Manhunt 2 for the PC. Just two console games, one for the obscure CD-i, have gotten the mark.
5% of games in 2010 rated M – ESRB [GameSpot. Chart via Gamespot]