Nigeria will start its first national census in 17 years at the end of March, as authorities in Africa’s most populous country seek updated data on the exact population and the size of different ethnic groups, an official said late on Friday. Nigeria’s estimated population is more than 200 million and the United Nations expects that to double by 2050. That would make Nigeria the world’s third most populous country, overtaking the United States. Census figures in Nigeria affect the sharing of oil revenues and political representation among the 36 states and 300 ethnic groups. Previous counts were discredited after disputes among the three main groups, the Fulani, Yoruba and Igbo. Nasir Isah Kwarra, chairman of the National Population Commission, told reporters census counting would be conducted from March 29 to April 2, more than a month after Nigerians go to the polls to vote for a new president. Nigeria initially planned the census in 2021 but authorities postponed the process on the grounds of widespread insecurity, especially in the north where an Islamist insurgency and kidnappings for ransom have been raging.