The 2000 United States Census was the twenty-second national census and was conducted by the United States Census Bureau. The census, which is mandated by the United States Constitution, is conducted every ten years and is used to determine the population and demographics of the United States. The 2000 Census was the first to be conducted primarily online, with some households receiving a paper questionnaire. The census counted a total population of 281,421,906 people, a 13.2% increase from the 1990 Census. The 2000 Census also collected information on a range of demographic characteristics, including race, ethnicity, age, and household composition. The results of the 2000 Census are used to determine the number of seats each state has in the United States House of Representatives and to distribute federal funds to state and local governments.