Each month another 800,000 people around the world celebrate their 65th birthday as the planet's population continues to age.

Global aging is occurring at a rate never seen before and we will need to pay close attention to how countries respond to the challenges and opportunities of growing older.

Gradual declines in fertility and increases in life span due to improved healthcare are driving a decades-long trend toward older populations that experts expect to continue throughout the 21st century.

While developed countries led this trend, the strongest growth in terms of aging populations is now occurring in developing nations, which together account for three-quarters of the world's overall gain in those living beyond age 65.

Italy now ranks first on the list of nations with the highest percentage (18.1%) of citizens over 65, nudging ahead of Sweden (17.3%), Greece (17.3%), Japan (17.1%) and Spain (16.9%). Other countries, many of them still developing, are expected to undergo an aging 'boom' in coming decades.

It is predicted that Singapore, for example, will experience a nearly 400% increase in citizens over the age of 65 by 2030, with similar rates predicted for Malaysia, Colombia, Costa Rica and the Philippines.

In terms of long life, Japan -- with an average life expectancy of 80.7 years -- continues to lead the world.

Those looking forward to many golden years might also consider a move to Singapore (average life expectancy 80.1 years), Australia (79.8), Sweden (79.6), or Canada (79.4). Average life span in the United States is now 77.1 years, according to the report, with the UK slightly higher at 77.7.

Ideally, old age should be comfortable and relatively worry-free, and the report found that about 75% of the world's countries do have some form of socialized pension plan in place. The priority governments place on taking care of their elderly varies widely nation to nation, however, with pensions equaling 15% of gross domestic product in Italy, 7.2% in the US, and 0.4% in Mexico.

Care of the elderly may be especially important in the developing world, the experts note, since disability rates among the old are rising in poorer countries, even as they fall in richer nations.

US Census Bureau Report An Aging World: 2001, December 13, 2001