a    2017
b    Refers to the Delhi metropolitan area that is not restricted to state boundaries (National Capital Territory), includes contiguous suburban cities and towns, such as Faridabad, Gurgaon, and Ghaziabad.
c    2018
d    Data classified according to ISIC Rev. 4.
e    Estimate.
f    Industrial workers.
g    2016
h    Data classified according to ISIC Rev. 3.
i    Data refer to fiscal years beginning 1 April.
j    2014
k    Data refers to a 5-year period preceding the reference year.
l    2015
m    Including refugees.
n    Data as at the end of December.
o    Break in the time series.
p    2013
q    2003
r    2004
s    Excluding nationals residing abroad.
t    Including nationals residing abroad.