The World Rankings for Sonic Adventure 2 were never launched. Although, the menu images for the menu bar of this website (which you clicked to get here) were commented out. So a replacement image and this page was made

If you have Codebreaker for Dreamcast you can use the following codes to enable the "World Rankings" menu option in the "extras" section of Sonic Adventure 2

005CCB09
000000000

You can see documentation of this on The Cutting Room Floor