The first census in the 20th century was carried out in 1918 and recorded a population of 647,500. Since the end of socialism, Mongolia has experienced a decline of total fertility rate (children per woman) that is steeper than in any other country in the world, according to recent UN estimations: in 1970–1975, fertility was estimated to be 7.33 children per woman, dropping to about 2.1 in 2000–2005. The decline ended and in 2005–2010, the estimated fertility value increased to 2.5 and stabilised afterwards at the rate of about 2.2–2.3 children per woman.