What is expected to happen to the number of people sixty years and older in the developed world by the year 2050? To what can this be attributed? (Site 1)

By the year 2050 the number of people aged 60 years and older will significantly increase by more than 1 billion.

This is attributed to better medical conditions, healthier lifestyles, advances in bio-tech etc.

In Europe, already 25% of the population is 60 and above and number is also rising in Japan.

By 2050 we will be able to see similar patterns emerge in more populous nations such as China, Pakistan and Nigeria.