a    Projected estimate (medium fertility variant).
b    2015
c    Data refer to "Urban area" (Greater London).
d    2017
e    2016
f    Data classified according to ISIC Rev. 4.
g    Estimate.
h    Calculated by the Statistics Division of the United Nations from national indices.
i    2014
j    Data refers to a 5-year period preceding the reference year.
k    Data as at the end of December.
l    Population aged 16 to 74 years.
m    2004
n    Shipments of coal and oil to Jersey, Guernsey and the isle of Man from the United Kingdom are not classed as exports. Supplies of coal and oil to these islands are, therefore, included as part of UK supply. Exports of natural gas to the Isle of Man included with the exports to Ireland.
o    Development Assistance Committee member (OECD).
p    Provisional data.