Arlington, VA is an urban county of about 26 square miles directly across the Potomac river from Washington, DC without any incorporated towns or cities. As of January 1, 2018, Arlington had an estimated population of 225,200, reflecting an increase of 8.5% since 2010. In 2006 CNN money ranked Arlington as the most educated city in 2006 with 35.7% of residents having held graduate degrees. The county is governed by a five-person County Board; members are elected at-large on staggered four-year terms. The Board appoints a County Manager, who is the chief executive of the County Government.