Blank Locations vs. Blank Location Fields

Is there a way to ensure that my data includes, say, 20% blank locations:

111 Main St, Anytown, CA 90001
                                                        <=== Blank location

instead of blank fields within a location:

111 Main St, , CA 90001
123 Hamner Ave, Norco, , 91720

How do you have your schema setup? Can you provide the link please?