Registered field - False vs blank field

In the Registered field when you run reports you will find adults listed as “false” or a blank field.
On an adult’s Profile page go to Registration Info EDIT
I’ve determined that if you check the registered box on the Edit drop down box Yes then uncheck the box and save, this adult will be listed as FALSE on reports. If this box has never been touched the adult will be listed with a blank field on reports.
Seems to be an odd. Makes sorting reports on Registered field difficult. Could it be fixed so that if box isn’t or hasn’t been checked everyone is FALSE not blank?