He's either cheating or he's not very good at estimating

Back in April when Mitt Romney filed his six month extension on 'disclosing' his taxes, he estimated his 2011 income was $20,901,075, and when he finally got around to filing, his income was down to $13,696,961. Ah, he was only off 53% and a little over $7 million.

Does he think everybody's stupid?