The values for the years 2012 to 2020 will be revised, and there is currently a break in the time series between 2020 and 2021. Mid-year population estimates relate to the usually-resident population. They account for long-term international migrants (people who change their country of usual residence for a period of 12 months or more) but do not account for short-term migrants (people who come to or leave the country for a period of less than 12 months).

This approach is consistent with the standard United Nations definition for population estimates which is based upon the concept of usual residence and includes people who reside, or intend to reside, in the country for at least twelve months, whatever their nationality.