Asia’s fourth-largest economy recorded just 0.7 births per woman late last year -– one of the lowest birth rates in the world and far below the replacement rate of 2.1 needed to sustain the current population.

That means South Korea’s population is ageing and shrinking rapidly.

Those aged 65 and older “account for 20% of the 51.2 million registered population, numbering 10 million”, the interior ministry said in a news release on Tuesday, placing South Korea alongside Japan, Germany and France as a “super-aged society”.

It also means the elderly population has more than doubled since 2008, when it numbered fewer than five million, according to the ministry.

Men account for 44% of the current 65-and-older group, the data showed.

The government has poured billions of dollars into encouraging more births, with Seoul authorities offering subsidies for egg freezing in one recent effort.

However, such efforts have failed to deliver the intended results and the population is projected to fall to 39 million by 2067, when the median population age will be 62.

Experts say there are multiple causes for the twin phenomena of low marriage and birth rates, ranging from high child-rearing costs and soaring property prices to a notoriously competitive society that makes securing well-paid jobs difficult.

The double burden on working mothers, who shoulder the bulk of household chores and childcare while maintaining their careers, is another key factor, they say.