A population and housing census began on December 31 in Estonia for the 11th time and will last until March 31, 2012. During the three months all the present residents of Estonia and their housing will be counted. The census is the only survey that provides comprehensive statistics on how many residents there are in Estonia, and in what areas and in what conditions they live. The first census in Estonia took place in 1881, and the last one in 2000. In the census of 1959 the data were processed with a computer for the first time. On the initiative of the United Nations residents of most world countries were counted in 2010 and 2011, with no census organised in only six countries.