Despite criticism, the Nigerian Economic and Financial Crimes Commission (EFCC) announced in May 2018, that 603 Nigerian figures had been convicted on corruption charges since Buhari took office in 2015. The EFCC also announced that for the first time in Nigeria's history, judges and top military officers including retired service chiefs are being prosecuted for corruption. In December 2019, the country's controversial ex-Attorney General Mohammed Adoke, who was accused of being bribed to grant oil licenses to Shell, was extradited back to Nigeria from Dubai and was immediately arrested. In January 2020, however, Transparency International's Corruption Perception Index (CPI) still gave Nigeria a low ranking of 146 out of 180 countries surveyed.