TOKYO (AP) – The proportion of Japanese aged 65 or older reached 21.0 per cent of the country’s population in 2005, surpassing Italy’s 20.0 per cent as the world’s highest, the government said yesterday.

The ratio of people under 15 also hit the world’s lowest level at 13.6 per cent, dipping below Bulgaria’s 13.8 per cent, the Ministry of Internal Affairs and Communications said in a preliminary report based on a nationwide census taken last year.

A plunging birth rate and an expanding elderly population pose serious concerns for Japan as it struggles to tackle a labour shortage and eroding tax base.

The elderly accounted for 26.82 million of Japan’s total population of 127.76 million, up 21.9 per cent from the previous census in 2000, the report said. The proportion of people under 15 fell 5.8 per cent to about 1.07 million.

The report also said the proportion of unmarried people went up in all age groups between 20 and 64, for both men and women.

Roughly three out of five women aged 25-29 were unmarried, while 32.6 of those aged 30-34 hadn’t tied the knot, the report said. Three out of four men aged 25-29 and just under half of men aged 30-34 were also unmarried.

Japan’s population dropped in 2005 for the first time on record, shocking officials and spurring a spate of measures to encourage women to have more babies.

The government began a five-year project last year to build more daycare centres, while encouraging men to take paternity leave. Towns and villages have also launched matchmaking services to get more people to marry.

But Japan’s birthrate in 2005 stood at a record low of 1.25 babies per woman in her lifetime, far below the 2.1 rate needed to keep the population steady.

Japan’s reluctance to open its borders to immigrants and refugees despite an urgent need for new workers to replace its aging work force has also compounded the problem.

Foreign residents accounted for only about 1.2 per cent of Japan’s 127 million people at the end of 2005, and a government panel may propose limiting the ratio of foreigners to three per cent of the country’s population.

The government has said roughly one in four Japanese may be aged 65 or older in 2015, and about one in three in 2050.