a    2017
b    2018
c    Data classified according to ISIC Rev. 4.
d    Estimate.
e    Calculated by the UN Statistics Division from national indices.
f    Break in the time series.
g    2016
h    Data classified according to ISIC Rev. 3.
i    2011
j    Data refers to a 5-year period preceding the reference year.
k    2015
l    Data as at the end of December.
m    Data revision.
n    2003
o    2009
p    2013
q    2004
r    2012
s    2014
t    2006
u    Excluding nationals residing abroad.