Two percent of 19-year-old women and 1.5 percent of those aged 18 had abortions in fiscal 2003.
A survey by the Health, Labor and Welfare Ministry released Tuesday shows that 40,475 minors under 20 had abortions in the reporting year, slightly down from the previous year but double the figure of 10 years earlier.
The ministry has been surveying the number of abortions since 1948. The latest survey was the first time in which it started counting the number for each age for those between 15 and 19, in an effort to get a clearer picture of the realities of minors having abortions.
A total 319,831 abortions were performed in Japan last year, down about 9,500 from the previous year.
Around 14,600 19-year-olds had abortions, compared with about 11,100 18-year-olds. There were 7,900 abortions among 17-year-olds.
Some 483 abortions were performed on children younger than 15, the survey found.
The rate of abortions per 1,000 people at age 19 was 19.9, the second highest following 20.2 for the age group from 20 to 24. The figure for those aged 18 was 15.7.
The figure for the 25-29 age group was 14.8, while for the 30-34 age group it was 13.3, the survey said.