Query: The state oil company NNPC was initially thought to owe how much to the government?
Context: More than $400 billion were stolen from the treasury by Nigeria's leaders between 1960 and 1999. In late 2013, Nigeria's then central bank governor Lamido Sanusi informed President Goodluck Jonathan that the state oil company, NNPC had failed to remit US$20 billion of oil revenues, which it owed the state. Jonathan however dismissed the claim and replaced Sanusi for his mismanagement of the central bank's budget.