Since mid-March, the U.S. Census Bureau has been asking people to answer the agency’s questionnaire, which asks about the number and demographics of people living in the household, online or by phone or mail. About 68 percent of Virginians have complied — the eighth-highest response rate among the states. But the statewide average masks vast differences among localities. In the Northern Virginia cities of Falls Church and Fairfax, 80 percent of the residents have filled out the census; in Accomack County, it’s just 35 percent. [My article for Virginia Mercury]