There are already 11 oil-producing states in Nigeria, according to Ventures Africa, with the majority of the country’s oil reserves in the Niger Delta, a southern swampland spanning several states. The West African country has seen its oil production slashed in 2016 by militant groups—including the Niger Delta Avengers—who claim to be campaigning for a fairer share of the nation’s oil wealth for impoverished communities living in the Delta. Combined with the fall in global commodity prices, Nigeria’s diminished oil production saw the country enter a recession in August. The managing director of the state oil corporation said Wednesday that militant attacks had cost the country more than 1.5 trillion naira ($4.8 billion) in lost revenues.