the actual list, if you trust the Examiner and Forbes, is:
http://washingtonexaminer.com/local/dc/6-10-richest-counties-us-are-dc-area1) Loudoun
2) Fairfax
3) Howard
...
6) Fairfax City (but that isn't a county?)
. . .
9) Arlington
10) Montgomery Burns
And, just below:
12) Stafford
13) Calvert
14) Prince William (have i got a land deal for you)
and, where the heck is Goochland (#16)?
Charles is #21.
When you see that list, you wonder, if the Springfield Mall development had blown up a bit earlier and the mixing bowl project finished a bit earlier, would the Springfield Mall site been a good location for a stadium?