FILE PHOTO: Heavy traffic passes through the Lagos-Abeokuta expressway in Ikeja district in Nigeria's commercial capital Lagos April 12, 2016.REUTERS/Akintunde Akinleye/File Photo
(This Jan. 21 story has been corrected to change one of the main ethnic groups to Hausa from Fulani in paragraph 3)
ABUJA (Reuters) - 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.
