On 3rd November 2001, Statistisk sentralbyr ̄(Statistics Norway) carried out a Population and Housing Census in Norway (Census 2001). The purpose for this nation-wide census is to illustrate how people live in Norway, provide information on the composition of the population and describe living conditions in the Norwegian society. Population and housing censuses have a long history in Norway. The first census was conducted in 1769 and the 2001 Census is the 21st. In the 2001 Census, both registers and questionnaires were used to gather information. Data from the census is also used to supplement and update the Central Population Register (CPR) and the Register of Ground Properties, Addresses and Buildings (GAB).