a    2019
b    2018
c    Estimate.
d    Data up to 2011 refer to former Sudan (including South Sudan) and data beginning 2012 is attributed to Sudan without South Sudan.
e    Data refers to a 5-year period preceding the reference year.
f    Including refugees.
g    Including South Sudan.
h    Data as at the end of December.
i    2017
j    2008
k    2009
l    Overestimated or based on overestimated data.
m    2005
n    Including nationals residing abroad.