No offence, but there is a 370 posts long thread about this exact subject.
The leader of this site even posted a link to the explanation in the first post of the thread. Here it is:
http://www.vgchartz.com/forum/post.php?post=3106154&page=6&postnum=18
(If that doesn't work, go here: http://vgchartz.com/forum/thread.php?id=99553&page=1 and read the first post)







