a    2017
b    Break in the time series.
c    2016
d    2010
e    Data classified according to ISIC Rev. 2.
f    Population aged 16 years and over.
g    2000
h    2003
i    Estimate.
j    2018
k    Areas not elsewhere specified.
l    Data refers to a 5-year period preceding the reference year.
m    2015
n    2013
o    2009
p    2012
q    Estimates should be viewed with caution as these are derived from scarce data.
r    Refers to the island of Saipan.
s    2004
t    Arrivals by air.