Well, as they always say, TIMTOWTDI ;) Personally, if you don't want to keep old scores lying around, I would always do a delete statement, then an insert to add in the new stores. IMHO, it's a bit less work (for you and the database). I mean, you could check to see if the update processed successfully, and if not, do an insert, but this requires a lot less thought ;)
You might also wish to explicitly issue a commit at the end of your script. While I haven't brushed up on the DBI documentation lately, assuming that the disconnect will do a commit for you just strikes me as a bad idea (that next rollback could be brutal. . . ). For safety sake, you might wish to add a $dbh->commit() before the disconnect.
And (just a writeup tip) I hope the connection information for MySQL is bogus. If not, I hope you change the username and password for database access before exposing your database to the world ;) Kinda related to that though, you might wish to check out How (Not) To Ask A Question by jeffa for that (not giving us your real username and password) and other good writeup tips.
Hope this was of some help :) Good luck!
MrCromeDome