Japan now has so many people over 100 that it is cutting costs by reducing the size of silver cups it presents to those who reach that age.

Last year, 19,769 people reached triple figures in the world's most rapidly aging country, compared with only 153 in 1963, the year when the cups were first presented.

"We realized there's not such a big difference in appearance if we cut the diameter from 10.5 to 9 cm (4.13 to 3.54 inches)," an official at the Health Ministry said. "We also had to think about how to continue to do this for an increasing number of people on a limited budget."

The cups are presented on September 15, a holiday designated Respect for the Aged Day, to people who have turned 100 in the past year.

The cost varies with the price of silver, but the Yomiuri newspaper said it was about 7,000-8,000 yen ($72-82) apiece, including a wooden presentation box.The Japanese are the world's longest-lived people, a phenomenon experts have attributed to a range of factors, including diet and widely available health care.

There are 36,436 people aged over 100 in a population of 127.8 million.