Photo by . . . every.seven . . .. A Newsweek report shows that 7 of the 10 richest counties in the country are in the D.C. metro region. Newsweek used data from the 2009 Census to inform their rankings. The richest county in the country is Virginia’s Loudoun County, with a median income of a staggering $114,204. Following are VA’s Fairfax County (number 2), MD’s Howard County (number 3), VA’s Arlington County (number…