U.S. Minor Outlying Islands

[jbrockmendel]

FIPS code 74
Abbreviation UM

https://en.wikipedia.org/wiki/Federal_Information_Processing_Standard_state_code

I think this is the only thing preventing mapping from state FIPS codes to county FIPS codes here.

If there is an interest, I'll volunteer to put together a PR for this.

[andyvan-trabus]

I would like this added, as well as Marshall Islands (MH, 68).