According to the UNPD’s 2008 Revision, the population of most developed countries is expected to remain almost
unchanged, at 1.28 billion, but that of less developed regions to rise from 5.6 billion in 2009 to 7.9 billion in 2050, with
a tripling of numbers in some of the poorest nations. Net migration from developing to developed countries is
projected to average 2.4 million people a year. Populations are continuing to age, with the numbers of people aged 60
or over expected to triple worldwide to 2 billion by 2050, and fertility is expected to drop, with a fall from 2.56
children per woman in 2005-2010 to 2.02 in 2045-2050 (below the replacement rate of 2.1 children).