Notes:

These charts include the 196 countries and territories with a population of 100,000 or more in 2009.

(1) The Median Age is the age that divides the population in two parts of equal size, that is, there are as many persons with ages above the median as there are with ages below the median.

(2) The child dependency ratio is the ratio of the population aged 0-19 to the population aged 20-64.

(3) The old-age dependency ratio is the ratio of the population aged 65 years or over to the population aged 20-64. All ratios are presented as number of dependants per 100 persons of working age (20-64).

(4) The total dependency ratio is the ratio of the sum of the population aged 0-19 and that aged 65+ to the population aged 20-64.

(5) The Life Expectancy at age 75 is the average number of years of life expected by a hypothetical cohort of individuals age 75 who would be subject during all their lives to the mortality rates of a given period. It is expressed as years.

(6) The Adult Mortality is defined here as the probability of dying between age 15 and age 60 (45q15) per 1000.

Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects: The 2010 Revision. New York

(Updated: 4 May 2011)