The U.S. Constitution requires a national census once every 10 years. The census is a count of everyone (all ages, races, ethnic groups, both citizens and non-citizens) residing in the United States: in all 50 states, Washington D.C., Puerto Rico, U.S. Virgin Islands, Guam, the Commonwealth of the Northern Mariana Islands, and American Samoa. Census data help determine locations for schools, roads, hospitals, child-care and senior citizen centers, and more. Businesses use census data to locate supermarkets, shopping centers, new housing and other facilities. Government officials use census data to allocate funding and grants to high-need areas and non-profit organizations. Through partnerships, the Census Bureau has a greater chance to reach every U.S. resident: educators are encouraged to help deliver the 2010 Census message from elementary schools to college campuses.