The proportion of senior citizens in South Korea has increased to nearly 11 percent in 2010, data showed Thursday, indicating that the country's population is aging at a fast pace.

According to the data by Statistics Korea, the proportion of those aged 65 or older accounted for 10.9 percent of the country's total population in 2010. It is higher than 7 percent in 2000 and 8.9 percent in 2005.

The agency earlier expected the ratio will continue to rise to 15.7 percent in 2020 and 32.3 percent in 2040.

The figures come amid growing fears that South Korea is fast becoming an aged society, in which more than 14 percent of the population is 65 or older. Korea became an aging society in 2000 when the ratio topped 7 percent.

Experts worry that the aging population, coupled with the low birthrate, poses a serious threat to the nation's economy as it could lead to fewer working people and increased spending on health and welfare.

The ratio of one-member households among senior citizens has more than tripled over the past two decades, data also showed.

The proportion of people who live alone among the age group jumped to 34.3 percent in 2010 from 10.6 percent in 1990, the data showed.

Poverty among seniors has also deteriorated, pointing to worsening living conditions for those in the age group.

Their relative poverty rate stood at 49.3 percent in 2012, up from 46 percent in 2006, the data showed. The rate measures the percentage of households that earn less than 50 percent of the median income.

The relative poverty rate in South Korea marked the highest among 33 member countries of the Organization for Economic Cooperation and Development (OECD). The OECD average is 12.8 percent, the data showed. (Yonhap News)