Seoul, Aug 23 (IANS): South Korea's population declined for the second consecutive year in 2021, while the number of single-person households continued to increase, government data revealed on Tuesday.

As of the end of 2021, the nation's registered population stood at 51,638,809, down 0.37 per cent from 51,829,023 tallied at the end of 2020, according to data compiled by the Ministry of Interior and Safety.

The latest census number marks the second consecutive drop after a 0.04 per cent on-year fall in 2020, as a record low number of births were surpassed by deaths to cause a natural decrease, reports dpa news agency.

The Ministry also attributed last year's drop to the government cancelling the resident registration numbers of some 143,000 people whose whereabouts have not been identified for a long time.

Of South Korea's 17 cities and provinces, only three reported an increase in population last year -- Incheon, Sejong and Jeju Island, the data showed.

The data also showed a 1.6 per cent on-year increase in the number of households to 23,472,895 last year.

That is largely attributed to the rise in the number of single-person households, which accounted for more than 40 per cent of the total for the first time, the data showed.

The data showed there were over 9.46 million households with one person last year, accounting for some 40.3 per cent, followed by households with two people with 23.9 per cent.

Households with four or more people accounted for 18.7 per cent.