The census is required by the Constitution, which has called for an "actual enumeration" once a decade since 1790. The 2020 population numbers will shape how political power and federal tax dollars are shared in the U.S over the next 10 years. The number of congressional seats and Electoral College votes each state gets are determined by census numbers. They also guide how an estimated $880 billion a year in federal funding is distributed for schools, roads and other public services in local communities. The demographic data are used by businesses to determine, for example, where to build new supermarkets and by emergency responders to locate injured people after natural disasters.