Births to those not married accounted for nearly 5 percent of all births last year, setting a new record high, while the total number of newborns dropped to a new low, data showed Thursday.

According to Statistics Korea, of the 230,028 babies born last year, 10,900, or 4.7 percent, were born to women who were not married, marking the highest proportion since records began in 1981. Babies born to people who were not married have steadily increased since 2020, reaching 9,800 in 2022, or 3.9 percent of total births. In 2021, the figure was 7,700, or 2.9 percent.

In contrast to the rise in births to those not married, the total number of births has been on the decline since the 1960s and 1970s. During one peak in 1971, there were 1,024,773 total babies born and a fertility rate -- measuring the average number of children born per woman aged 15-49 -- of 4.54 children.

Last year, the total number of births dropped to 230,028, a 7.7 percent decrease from 249,200 in 2022, marking the lowest figure since the agency began collecting data in 1970. In 2020, the nation saw the annual number of childbirths fall below the 300,000 mark for the first time ever.

The fertility rate also dipped to a fresh low of 0.72 last year from 0.78 the previous year. Seoul had the lowest fertility rate at 0.55, followed by Busan at 0.66. South Jeolla Province and Sejong City recorded the highest fertility rates: both 0.97.

South Korea saw a total of 193,673 marriages registered last year, up from the 191,690 marriages recorded in 2022.

Among newborns last year, first children accounted for 60.2 percent, up 2 percentage points from 2022. Second children comprised 32.3 percent, down 1.4 percentage points, while third children made up 7.5 percent.

The average ages of mothers and fathers last year were 33.6 and 36.1, respectively, both increasing by 0.1 from the previous year.