a    2017
b    2019
c    2018
d    Estimate.
e    Base: 2016 = 100
f    Data refer to 7 cities only.
g    2016
h    Data refers to a 5-year period preceding the reference year.
i    Refers to foreign citizens.
j    Data as at the end of December.
k    Data revision.
l    2014
m    2009
n    Data are as at 1 January of reporting year.
o    Partial data.
p    Government only.
q    Break in the time series.
r    Arrivals of non-resident tourists by air.