The number of people who turned 20 years old, the legal age of adulthood in Japan, as of Jan. 1 came to 1.33 million, down about 20,000 from a year earlier and a record low for the second consecutive year, the Internal Affairs and Communications Ministry said Monday.

The new adults -- 680,000 men and 650,000 women -- celebrated the start of adulthood at ceremonies held nationwide Monday marking Coming-of-Age Day, a national holiday.

They account for 1.04 percent of Japan's total population, down 0.02 percentage point from a year earlier to mark a record low for a third straight year.

The decline in the number of new adults reflects the low birthrate in Japan.

The previous record low of the new adult population was 1.35 million as of Jan. 1 last year, which was the lowest in 21 years at that time since 1.36 million as of Jan. 1, 1987, when people born in 1966 became adults.

The year 1966 was a year of "Hinoe-Uma" which is considered to be inauspicious for women, according to Japanese superstition.