Rivers State is the sixth-largest geographic area in Nigeria according to 2006 census data. The state has an indigenously diverse population with major riverine and upland divisions. The dominant tribes are: Ikwerre, Ogoni, and Ijaw, representing three dominant Ethno-Linguistic blocs in the State, in no particular order. Upland Rivers State, covering about 45%, is composed mainly of Igbo/Igboid speaking people, and Ogoni. The riverine, including most of the state's towns and villages surrounded by water, is moderately inhabited. It covers approximately 39% of the total land mass and is home to the Ijaw people.