a    Projected estimate (medium fertility variant).
b    2015.
c    2016.
d    Data classified according to ISIC Rev. 4.
e    Estimate.
f    Rural and urban areas.
g    Series linked to former series.
h    2014.
i    Data refers to a 5-year period preceding the reference year.
j    Refers to foreign citizens.
k    Including refugees.
l    Data as at the end of December.
m    In 2014, a revised GDP series was published following a statistical rebasing exercise (the base year changed from 1990 to 2010). Nigeria has emerged as Africa's largest economy, with a GDP increase of 89% for year 2013.
n    2009.
o    2013.
p    2011.
q    Excluding business enterprise.
r    2007.
s    2004.