Almost one in four households in Seoul consisted of just one person last year, the city’s census found Thursday.

Single-person households jumped from 4.5 percent in 1980 to 23.8 percent in 2010, according to the Seoul Metropolitan Government.

Their number increased more than 10-fold between 1980 and 2010, while the total population of Seoul nearly doubled in the same period.

“A growing number of single people are choosing not to marry or get married late. The increasing rate of divorce and the aging population may have also affected the recent trend,” said a city official.

In Seoul, the number of married people decreased 35 percent between 1990 and 2009. However, the city’s divorce rate almost doubled during the same period.

Amid a rapidly aging population here, there was an increase in the number of senior citizens living alone from 11.8 percent in 1985 to 24.1 percent in 2005.

The average number of family members also continued to decrease from 4.47 in 1980 to 2.76 in 2010.

The trend was also confirmed in a separate survey conducted recently on 26,000 Seoul citizens aged 15 or older.

Asked if marriage was essential, 63.3 percent of the respondents said yes, while 33.3 percent considered marriage “optional.”

More than half the respondents, or 55.2 percent, said they were opposed to divorce.

Of the senior citizens surveyed, eight in 10 said they didn’t want to live with their children.

Only 30.4 percent of those asked said they felt responsible for supporting their aging parents, a drastic decrease from 60.7 percent in 2006.

Half the respondents said the responsibility needs to be shared with the government, while 15 percent said elderly people should look out for themselves.

By Lee Ji-yoon (jylee@heraldcorp.com)