South Korean children wearing Santa Claus outfits perform during a ceremony to launch a year-end fundraising campaign of the Salvation Army at Gwanghwamun square in Seoul on November 30, 2018. (Photo: AFP)

SEOUL, March 24 (Xinhua) -- South Korea's fertility rate broke record lows for five straight years last year as people refrained from getting married and having children, official data showed Thursday.

The total fertility rate, which gauges the average number of babies that a woman is expected to have during lifetime, fell 0.03 over the year to 0.81 in 2021, according to Statistics Korea.

It was the lowest since relevant data began to be compiled, breaking the previous record lows for the fifth straight year since 2017.

The record-low fertility rate came as the younger generation delayed marriage and having children amid the higher cost to bring up children, the stubborn youth unemployment and the soaring housing prices.

The country's population totaled 51.75 million in 2021, after peaking at 51.84 million in 2020.

The average number of family members per household was 2.34 in 2020, down from 3.12 tallied 20 years earlier.

The percentage of single-person households to the total continued to rise from 15.5 percent in 2000 to 23.9 percent in 2010 and 31.7 percent in 2020 respectively.

Life expectancy for South Koreans stood at 83.5 years in 2020, keeping a continued upward trend from 81.8 in 2014, 82.4 in 2016, and 82.7 in 2018 each.

Private education participation rate among primary and secondary school students came in at 75.5 percent in 2021, up 8.4 percentage points from the previous year.

The monthly average cost to attend private cram schools amounted to 367,000 won (300 U.S. dollars) in 2021, up 21.5 percent from a year earlier.