New U.S. Census figures show that the Washington area’s population boom has slowed and even, in the case of D.C. and Prince George’s County, has reversed.

D.C.’s population dipped by about 500 people from July 2005 to July 2006, evidence that some people no longer can afford to live in a city that is going through a rebirth, said Brett Williams, a professor of anthropology at American University.