a    Projected estimate (medium fertility variant).
b    2015.
c    2016.
d    Estimate.
e    All cities.
f    2014.
g    Data classified according to ISIC Rev. 3.
h    Break in the time series.
i    Asia not elsewhere specified.
j    North and Central America not elsewhere specified.
k    Other Europe, not elsewhere specified.
l    Data refers to a 5-year period preceding the reference year.
m    Including refugees.
n    Refers to foreign citizens.
o    Data as at the end of December.
p    Data revision.
q    2001.
r    2008.
s    2009.
t    Population aged 12 to 65 years.
u    Partial data.
v    R&D budget instead of R&D expenditure or based on R&D budget.
w    2004.
x    The data for crude oil production include 50 per cent of the output of the Neutral Zone.