The recidivism rate for juvenile offenders has been on a steady rise in recent years, police said Thursday.

The second conviction rate for juvenile offenders arrested over the past four years rose from 32.4 percent in 2009 to 35.5 percent in 2010, 36.9 percent in 2011 and 37.3 percent in 2012, the National Police Agency said in a report submitted to a ruling party lawmaker.

The share went up to 41.9 percent in the first eight months of this year alone.

The number of youth convicted for more than nine criminal offenses more than doubled to 3,362 in 2012 from 1,597 in 2009, with the number reaching 2,923 as of the end of August.

The entire number of youth offenders arrested began to rise again to 107,018 in 2012 after declining for three consecutive years from 118,058 in 2009 to 94,862 in 2010 and 86,621 in 2011.

The report also showed theft, assaults and rapes constituted most offenses by juveniles last year, followed by robbery, arson and murders.

"A peer culture that one's criminal records are considered as a sort of decoration is spreading among some young people," Rep. Kang Ki-youn of the Saenuri Party, who released the police report, said in a statement.

"Schools of all levels need to come up with aggressive measures to prevent this by including anti-crime education in their regular curriculum for instance," he said. (Yonhap News)