The number of Japanese under the age of 15 sank to a new low of 16.49 million as of April 1, down 150,000 from the previous year, while the overall population contracted for the 32nd straight year, government data showed Saturday.

Of this total, 8.44 million were male and 8.04 million female, according to the data released by the Internal Affairs and Communications Ministry on the eve of Children’s Day.

The proportion of children under age 15 relative to the total population dropped 0.1 percentage point year-on-year to 12.9 percent, marking the 39th consecutive annual decline, the ministry said.

The figure was the lowest among major countries with a population in excess of 40 million. According to the 2011 edition of the U.N. Demographic Yearbook, the comparable ratio in the United States came to 19.6 percent, followed by China at 16.5 percent and Germany with 13.2 percent.

Meanwhile, the distribution of children by age assumed an inverted pyramid shape, the ministry data revealed.

The population gradually decreased from 3.55 million between the ages of 12 and 14 to around 3.4 million between age 9 and 11, and to 3.17 million between age 3 and 5. For children aged up to 2, the figure stood at 3.16 million.

By prefecture, only Tokyo and Okinawa posted an annual increase in the number of children under age 15 as of Oct. 1 last year. The figure rose by 3,000 in the capital and by 1,000 in Okinawa.

At 17.6 percent, Okinawa also had the highest proportion of children younger than 15 relative to its total population, followed by Shiga Prefecture with 14.8 percent and Saga Prefecture at 14.4 percent.

By contrast, Akita Prefecture, Tokyo and Hokkaido had the lowest ratios, at 11.1 percent, 11.3 percent and 11.7 percent.