The governors of the 17 southern Christian states have launched a lawsuit to gain control over the oil revenues obtained from wells located in the south. Most of the oil revenue comes from fields in the south and the federal government controls the income. Much of the money has been lost to corruption. Some 95 percent of Nigeria's export earnings come from oil. The government has offered the southern states 13 percent of the revenue. The Islamic states in the north have always gotten a share of the money, often an excessive share as many of the national leaders for the past four decades have been northerners.