Between January 2010 and September 2015, the country spent a total sum of N15.97tn on the importation of petroleum products such as petrol, diesel and kerosene.
The figures were released by the National Bureau of Statistics on Friday in Abuja.
Of the N15.97tn, the NBS, in its Petroleum Products Import Statistics Report covering 2010 to 2015, stated that N12.53tn was spent importing 102.37 billion litres of petrol.
In the report, a copy of which was made available to our correspondent, the bureau said the nation spent N1.51tn to import 15.21 billion litres of fuel in 2010, while N2.71tn was used to import 20.77 billlion litres of fuel in 2011.
For the 2012, 2013 and 2014 fiscal years, the report claimed that the country spent N2.18tn, N2.33tn and N2.35tn importing 15.78 billion, 17.56 billion and 18.99 billion litres of petrol respectively.
It added that within the first nine months of 2015, N1.45tn had been spent to import 14.05 billion litres of petrol.
Details of the last three months of 2015 have yet to be compiled by the bureau.
For Automotive Gas and Oil otherwise known as diesel, the NBS report said the country spent a total of N2.17tn importing 16.67 billion litres within the six-year period.
A breakdown of the diesel imports within the six-year period showed that N290.49bn was spent to import 2.9 billion litres of diesel in 2010, while N475.2bn and N318.2bn was spent importing 3.1 billion and 2.18 billion in 2011 and 2012 respectively.
For 2013, 2014 and the first nine months of 2015, the NBS report stated that N328.6bn, N452.6bn and N305.29bn was spent to import 2.34 billion, 3.18 billion and N2.96 billion litres of diesel respectively.
For importation of kerosene, the report claimed that the country spent N1.27tn on importation of 9.45 billion litres of the product between January 2012 and the first nine months of 2015.
A breakdown of the kerosene imports within the period showed that 2.57 billion litres were imported for N376.8bn in 2012 while N375.8bn and N400.04bn was spent on the importation of 2.65 billion and 3.06 billion litres of kerosene in 2013 and 2014 respectively.
For the first nine months of 2015, the report added that the nation imported 1.16 billion litres of kerosene at a cost of N118.74bn.