Select Field: Only show if data

Hi,

I have created an extensive list of cities which will ease and improve consistency of my data entry. For now (an for a long time to come), many of the cities will not have been added to any articles.

On the front-end, I want the drop-down to only show options in the select box if there are records in the database.

I hope this makes sense.

Any help would be appreciated.

Thanks,

Stephanie