Crime plummeted to a postwar low in 2015 but the increase in offenses committed by seniors remains an issue, the annual White Paper on Crime revealed on Friday.

According to the Justice Ministry report, the number of crimes sank 9.4 percent to 1.09 million compared with the previous year, stretching the downtrend to 13 consecutive years.

By category, robbery topped the list with 807,560 cases, or 73.5 percent of the total, followed by property damage, fraud and assault.