Trends in ageing of the population and the life expectancy after retirement: A comparative country-based analysis.

Background: During the 20(th) century, the share of elderly in the total population of the Earth has increased steadily. It is expected that this trend will continue in the 21(st) century. In 1950, the elderly (persons aged 60 years and older) were 8% of the world population; in 2000, is already 10%; and in 2050, according to United Nations projections, the proportion will reach 21%.