Issue with relating tables in PowerPivot

I am fairly new to PowerPivot in Excel and I was wondering about how you could use two tables of unrelated data in a pivot table.  I understand about how you can relate two tables like Customer and CustomerOrder that share a common key, but what about something like this:

Claims Table:
Claim Number
Claim Type
Year of Loss
State
County
Zip Code

Population Table:
Population Count
Year of Census
State
County
Zip Code

There isn't a true key that connects these Tables but they have many fields in common.  So if I was to list Florida Hurricane claims by loss year in a Pivot table is there any way to also list the Population for Florida for the same years?  Is there a solution that would automatically switch if I changed from State = Florida to County = DUVAL?  Could this be done with a DAX expression?