The 66 million people aged eighty or over present in the world today are destined to go up to 370 million in 2050, when there will be 2.2 million centenarians among them (UN estimate 1998).
The lengthening of the average life on one side and the decrease in the birth rate on the other has brought about an unparalleled demographic change: the numbers of elderly are in constant increase and the numbers of young people are decreasing. This phenomenon, which started in the Northern hemisphere in the early 1970s now also affects the Southern hemisphere, in which it is even more rapid. In fact, the persons who reach and exceed 60 years of age increased in 1995 by more than 12 million: nearly 80% of this change affects the developing countries. Recent UN studies are showing more downward corrections in the forecasts of population increase in the next decades. In the report on the state of world-wide population 1998, a population slow down. At this stage, only in a restricted number of African countries is the birth rate still high. Elsewhere, from Asia to the Latin America, it slows down more and more.
In India, for example, in 1990 the population over-65 as a percentage of the 15-64 age group was only 7.3%. In the dependency ratio will rise to 2050 the 23.2%. In China the ratio will rise from 8.4% to 31% and in Brazil from 7.1% to 28.9%.
The aged (over 60) in the world