a    Projected estimate (medium fertility variant).
b    2015.
c    Refers to Seoul Special City.
d    2016.
e    Data classified according to ISIC Rev. 4.
f    Estimate.
g    Break in the time series.
h    Index base: 2005=100.
i    2014.
j    Excluding water and waste management.
k    Data refers to a 5-year period preceding the reference year.
l    Refers to foreign citizens.
m    Data as at the end of December.
n    2009.
o    Population aged 3 years and over.
p    Population aged 16 to 74 years.
q    Excluding social sciences and humanities.
r    2004.
s    Including nationals residing abroad and crew members.
t    2012.
u    Development Assistance Committee member (OECD)
v    Provisional data.