Here is the official list of Top Ten Fastest Growing Economies in Africa for the year 2018 as powered by World Bank, Brookings Institution and IMF.

[1] Ghana  – 8.3%

[2] Ethiopia – 8.2%

[3] Cote d’Ivoire – 7.2%

[4] Djibouti – 7.0%

[5] Senegal – 6.9%

[6] Tanzania – 6.8%

[7] Sierra Leone – 6.3%

[8] Burkina Faso – 6.0%

[8] Benin Rep – 6.0%

[9] Rwanda – 5.9%

[10] Niger Rep – 5.2%

P.S
[41] NIGERIA – 1.9%

Nigeria was Number [1] in 2012, 2013, 2014 and 2015.
Also, Nigeria was the 3rd Fastest growing Economy in the World in 2014 now, the 88th.