a    2017
b    Refers to Muscat governorate.
c    2018
d    Estimate.
e    2016
f    Data classified according to ISIC Rev. 3.
g    2014
h    Areas not elsewhere specified.
i    Data refers to a 5-year period preceding the reference year.
j    2015
k    Refers to foreign citizens.
l    Data as at the end of December.
m    2009
n    Population aged 5 years and over.
o    2004