The number of reported sex crimes in 2015 has more than doubled over the past decade, according to a new governmental report, triggering calls for enhanced measures to prevent them.

While other felonies -- arson, robbery and murder -- saw a decline during the period, sex crimes soared by 117.6 percent from 14,277 in 2006 to 31,063 in 2015, according to the 2016 White Paper on Crime published by Institute of Justice.

The total number of offenses increased by 10.5 percent from 1,829,211 in 2006 to 2,020,731 in 2015. Among them, felonies surged by 61.8 percent from 21,720 in 2006 to 35,139 in 2015, due to a hike in the number of sex crimes.

Sex crimes accounted for 88.4 percent of the felonies that took place in 2015, followed by arson (4.7 percent), robbery (4.2 percent) and murder (2.7 percent).

Murder cases dropped 10 percent from 1,064 in 2006 to 958 in 2015. Robberies saw a 68.6 percent decrease, while arson cases were down 2.3 percent during the same period, the report showed.

“Over the past decade, there was a noticeable upward trend in the number of sex crimes. There needs to be stronger policing to prevent the soaring number of sex crimes,” the report said.

The jump in sex crimes could mean an actual rise in the offenses committed, but there are other contributing factors, it pointed out.

“The enactment of sex crime-related laws and revisions to them as well as the increase in the number of people reporting sex crimes to authorities are also reflected in the number,” it said.

The biggest group of victims of heinous crimes were women. The portion saw a steady growth for six years, making up 82.9 percent in 2010 and 88.9 percent in 2015.

Nearly 5 percent of the victims of sex crimes in 2015 were children aged 12 or younger and 86.3 percent of them were girls.

Unlike offenders of other heinous crimes, those committing sexual offenses tend to be more highly educated and first-time offenders. A majority of the sex offenders (33.6 percent) were university graduates. Some 37 percent had no previous criminal records in 2015.

The indictment rate for felonies stood at 47.8 percent in 2015, down 4.5 percentage points from the previous year, meaning the prosecution only filed charges against roughly half the cases.

The number of crimes committed by women was 353,977 in 2015, a rise by 29.8 percent from 2006. The number of crimes committed by the mentally challenged also increased by 11.3 percent, standing at 7,016.

In 2015, a total of 37,928 foreigners committed crimes, a rise from 22.6 percent from a year earlier. The major types of offenses were robbery, fraud, violence and injury. The prosecution indicted 37 percent of the suspects in 14,263 cases. It is a similar indictment rate to that of all criminal suspects in Korea, which stands at 36.8 percent.

A total of 1,736 Koreans were caught committing offenses abroad in 2015, an 11.9-percent increase from a year earlier. The types of crimes were fraud, violence and injury, robbery and drugs.

The number of Koreans subject to crimes abroad has also seen a 39.4-percent hike in 2015 from the previous year. From 2011 to 2015, a total of 144 Korean nationals were killed overseas, with 33.3percent in the Philippines, followed by 17.4 percent in the US and 11.1 percent in China.

The ministry publishes the White Paper on Crime annually using statistics compiled by the prosecution and the judiciary to examine the trend of crimes and types of criminals -- key information for the government to make policies on criminal justice.

By Ock Hyun-ju (laeticia.ock@heraldcorp.com)