those are production numbers combined with shipment numbers, which means they counted some units twice.
EDIT: ok I have no clue where this number is coming from. They didn't quote the 51.6m shipped number, and they have no source posted, and they don't track sales. If they were quoting the 51.6m, then this thread would expalin everything http://www.vgchartz.com/forum/thread.php?id=58704&page=1
oh, and the wosrt thing, is that people at kotaku take the sales as fact without any source, even though the site doesn't claim to track sales.








