The Federal Inland Revenue Service said it generated N12.62 trillion in revenue in the past three years.
The breakdown of the amount showed that N3.3 trillion was generated in 2016, N4.02 trillion in 2017 and N5.32 trillion was realised in 2018, making it the highest revenue generated in the last three years.
The Service indicated that non-oil revenue increased to N2.149 trillion in 2016, N2.5 trillion in 2017 and N2.852 trillion in 2018.