Nigeria has also been pervaded by political corruption. It was ranked 143 out of 182 countries in Transparency International's 2011 Corruption Perceptions Index; however, it improved to 136th position in 2014. 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. A Senate committee also found Sanusi’s account to be lacking substance. After the conclusion of the NNPC's account Audit, it was announced in January 2015 that NNPC's non-remitted revenue is actually US$1.48billion, which it needs to refund back to the Government.