a    2017
b    Refers to the population of Brussels-Capital Region and "communes" of the agglomeration and suburbs.
c    2019
d    2018
e    Data classified according to ISIC Rev. 4.
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    Calculated by the UN Statistics Division from national indices.
k    2016
l    Data refers to a 5-year period preceding the reference year.
m    Data as at the end of December.
n    Data are as at 1 January of reporting year.
o    Users in the last 3 months.
p    Population aged 16 to 74 years.
q    Provisional data.
r    Break in the time series.
s    Development Assistance Committee member (OECD).