BISMARCK, N.D. — North Dakota’s crime rate per capita last year rose 9.8 percent from 2014 and has more than doubled in three years, according to data released Thursday by the state Attorney General’s Office.

The annual report, which provides statistics for crimes ranging from murder to car thefts and other property crimes, shows that crime was up in most categories. The numbers of such offenses reported by law enforcement agencies rose to 14,866 in 2015, compared with 13,778 in 2011.

Attorney General Wayne Stenehjem historically has held news conferences announcing the annual crime statistics, but the data was posted on the agency’s website Thursday afternoon. Stenehjem was out of the office and did immediately return telephone calls seeking comment.

There were 21 murders in North Dakota last year, up from 19 in 2014 and the most since 1999 when there were 22. The state typically averages about a dozen murders a year.

North Dakota law enforcement agencies reported 31,648 arrests in 2015, up from 30,406 in 2014.

Aggravated assaults, which are felony crimes involving fights in which the victims are seriously injured, had been increasing in North Dakota for more than a decade but dropped for the first time in 2014 to 1,145. In 2015, aggravated assaults continued the longtime upward trend, with 1,185.

Drug arrests rose from 4,000 in 2014 to 4,382 last year, a nearly 10 percent increase. Drug arrests have nearly doubled in the past decade, data show.

For the third consecutive year, drunken driving arrests dropped; there were 6,229 drunken driving arrests in 2015, down from 6,705 in 2014. Authorities have attributed the drop to tougher drunken-driving laws passed by the Legislature in 2013.