a    2017
b    2019
c    2018
d    Data classified according to ISIC Rev. 4.
e    Including taxes less subsidies on production and imports.
f    Excludes publishing activities. Includes irrigation and canals.
g    Excludes repair of personal and household goods.
h    Excludes computer and related activities and radio/TV activities.
i    Estimate.
j    Urban areas.
k    2016
l    Data refers to a 5-year period preceding the reference year.
m    Data as at the end of December.
n    Figures for asylum-seekers in the United States of America pertain to mid-2019 for claims reported by the Department of Homeland Security and end-2018 for claims reported by the Executive Office for Immigration Review.
o    Data revision.
p    2014
q    Total refers to all voting members of the House of Representatives.
r    Data are as at 1 January of reporting year.
s    Population aged 3 years and over.
t    Do not correspond exactly to Frascati Manual recommendations.
u    Including overseas territories.
v    Oil and coal trade statistics include overseas territories.
w    Break in the time series.
x    Development Assistance Committee member (OECD).