The population of Bhutan had been estimated based on the reported figure of about 1 million in the 1970s when the country had joined the United Nations and precise statistics were lacking. Thus using the annual increase rate of 2–3%, the most population estimates were around 2 million in the year 2000. A national census was carried out in 2005 and it turned out that, 672,425 people lived there. Consequently, United Nations Population Division had down-estimated the country's population in the 2006 revision for the whole period from 1950 to 2050.