Here is some additional information. Basically the same....

https://bitcointalk.org/index.php?topic=178608.0


And here is a link to a spreadsheet that list when the ranks are updated in biweekly dates.

https://docs.google.com/spreadsheets/d/1dDySMB2lsOIIkUXuax2rXL30gv656E4xTsFcC2zQHkg/pubhtml