Management Reporter - Removing old Budget Models in Budget Drop Down List

In MR 2012 with AX 2012, is there a method to remove old Budget Model Codes from the drop down list in the Column Definition? We put up new budgets a few times a year, and the list is becoming extremely large. You can not delete a Budget Model when there are Budget Entries for it, and stopping it does not remove it from the list.

Any ideas?