a    2017
b    2018
c    Estimate.
d    2016
e    Areas not elsewhere specified.
f    Data refers to a 5-year period preceding the reference year.
g    2015
h    Refers to foreign citizens.
i    Including refugees.
j    Data as at the end of December.
k    2004
l    2007
m    Excluding victims of terrorist attacks.
n    2013
o    2000
p    Excluding business enterprise.
q    Excluding private non-profit.
r    Based on R&D budget instead of R&D expenditure.
s    2014
t    2001