The average age of teachers in Seoul rose 2.1 years in the last decade, according to data released Monday.

A report from the Seoul Metropolitan Office of Education showed that the average age of kindergarten, elementary, middle and high school teachers in Seoul reached 41.5 in 2012, up from 39.4 in 2002 and 40.9 in 2007.

Since 2002, the number of teachers over 50 almost doubled from 11,630 to 21,744.

For the first time in 2012, the number of teachers in their fifties exceeded those in their twenties. During that time, the number of educators in their twenties fell by 8.4 percent, from 14,173 to 12,984. Their overall percentage also fell from 19.8 percent of all teachers to 16.7 percent.

The percentage of teachers in their thirties and forties also dropped by 2.7 percent and 6 percent, respectively.

“The number of teachers of retiring age is rising steadily, but the number is still small compared to the number of newly employed teachers,” said an education official. “Also, the annual teacher certification is growing harder to pass due to fierce competition. This leads to people becoming teachers at an older age,” the official added.

The low fertility rate and dwindling number of students also contribute to fewer new teachers. Korea’s youth population reached its peak at 14 million in 1980 but since then has steadily declined to 10.2 million in 2012, according to the Ministry of Gender Equality and Family. Korea’s fertility rate is the world’s seventh lowest with 1.24 children per woman, according to data compiled by Statistics Korea.

By Lee Sang-ju (sjlee370@heraldcorp.com)