World Urbanization Prospects

Variable	Definition
Total population	De facto population in a country, area or region as of 1 July of the year indicated. Figures are presented in thousands.
Urban Population	De facto population living in areas classified as urban according to the criteria used by each area or country. Data refer to 1 July of the year indicated and are presented in thousands.
Rural population	De facto population living in areas classified as rural. Data refer to 1 July of the year indicated and are presented in thousands.
Percentage urban	Urban population as a percentage of the total population.
Percentage rural	Rural population as a percentage of the total population.
Total annual growth rate	See: Average annual rate of change of the total population
Urban annual growth rate	See: Average annual rate of change of the urban population
Rural annual growth rate	See: Average annual rate of change of the rural population
Average annual rate of change of the total population	Average exponential rate of growth of the population over a given period. It is calculated as ln(Pt/P0)/n where n is the length of the period and P is the population. It is expressed as a per cent.
Average annual rate of change of the urban population	Average exponential rate of growth of the urban population over a given period. It is calculated as ln(UPt/UP0)/n where n is the length of the period and UP is the urban population. It is expressed as a per cent.
Average annual rate of change of the rural population	Average exponential rate of growth of the rural population over a given period. It is calculated as ln(RPt/RP0)/n where n is the length of the period and RP is the rural population. It is expressed as a per cent.
Average rate of change of the percentage urban	Average exponential rate of change of the percentage urban over a given period. It is calculated as ln(PUt/PU0)/n where n is the length of the period and PU is the percentage urban. It is expressed as a per cent.
Average rate of change of the percentage rural	Average exponential rate of change of the percentage rural over a given period. It is calculated as ln(PRt/PR0)/n where n is the length of the period and PR is the percentage rural. It is expressed as a per cent.
Urban agglomeration	A type of urban settlement defined by the de facto population contained within the contours of a contiguous territory inhabited at urban density levels without regard to administrative boundaries. It usually incorporates the population in a city or town plus that in the suburban areas lying outside of but being adjacent to the city boundaries.
Metropolitan area	A type of urban settlement defined by both the contiguous territory inhabited at urban levels of residential density and additional surrounding areas of lower settlement density that are also under the direct influence of the city (e.g., through frequent transport, road linkages, commuting facilities etc.).
City proper	A type of urban settlement defined according to legal/political boundaries and an administratively recognized urban status that is usually characterized by some form of local government.
Capital cities	The designation of any specific city as a capital city is done solely on the basis of the designation as reported by the country or area. The city can be the seat of the government as determined by the country. Few countries designate more than one city to be a capital city with a specific title function (e.g., administrative and/or legislative capital).
Urban agglomerations annual growth rate	See: Average annual rate of change of urban agglomerations
Average annual rate of change of urban agglomerations	Average exponential rate of growth of the population of urban agglomerations over a given period. It is calculated as ln(PUAt/PUA0)/n where n is the length of the period and PUA is the population of urban agglomerations. It is expressed as a per cent.

Department of Economic and Social Affairs

Population Division

World Urbanisation Prospects 2018