Seoul’s population fell below 10 million for the first time in 32 years, as the number of foreign residents in the city sharply dropped amid the COVID-19 pandemic.

The city government said Wednesday that its population as of late last year reached 9.91 million, down 99,895 people from the same period a year earlier. It is the first time in 32 years that the capital’s population sat below 10 million, since it breached that mark at 10.29 million in 1988.

By the end of 2020, Seoul had some 9.67 million residents with Korean nationality and 242,623 residents of foreign nationalities. The number of households nonetheless rose 2 percent to 4.42 million, with an average of 2.19 people in a household, down 0.06 from 2019.

The population figure is based on the number of those registered as Seoul residents, including foreigners on student or work visas who reside in Seoul for more than three months.

The capital had hailed itself as a city of 10 million residents for years, reaching its peak of 10.97 million in 1992. But its population has steadily fallen since then due to a declining birthrate and aging population, with the number of Korean nationals in Seoul falling below 10 million in 2016.

The Seoul Metropolitan Government explained that the latest drop is largely due to the exodus of foreign residents due to COVID-19 pandemic. The number of those coming to work or study in Seoul sharply dropped, with the virus disrupting flights and academic plans for Korea as well as most other countries.

While the number of domestic residents fell 0.62 percent on-year, the number of foreigners dropped 13.93 percent. The greatest drop among foreign nationals was seen from the number of Chinese, with 32,000 people leaving Seoul throughout 2020.

The latest population analysis also showed that the Seoul population continued to age throughout last year, the city government said.

The proportion of those aged 65 and above reached 15.8 percent last year, significantly up from 14.1 percent in 2018 and 9.5 percent in 2010. Officials said 23 of 25 districts in the city saw their proportion of aged people reach more than 14 percent.

According to the United Nations, a society can be defined as an “aged society” when the share of those 65 and older accounts for more than 14 percent of the total population. A society is categorized as a “superaged society” when that proportion exceeds 20 percent.

While the number of those aged 4 or below fell 10.2 percent from a year earlier, the number of those aged between 85 and 89 surged 11.4 percent.

“We shouldn’t put significance on the 10 million population but rather continuously monitor social changes on what the population trend will bring as well as prepare related policies,” said Lee Won-mok, head of the smart city policy bureau at the city government.

By Ko Jun-tae (ko.juntae@heraldcorp.com)