User blog comment:Planterobloon/User Levels/@comment-5334494-20130521012731

So, I'm assuming it's:

Rank 7 - 500 edits

Rank 8 - 1,000 edits

Rank 9 - 2,500 edits

Rank 10 - 5,000 edits

Rank 11 - 10,000 edits (I don't think anyone is going to get that far :P)