ATHENS, Ga. (AP) — Officials with the Georgia Bureau of Investigation say an analysis shows the number of deaths they handled in 2013 involving drug overdoses was lower than in each of the previous five years.

However, the analysis also found a subgroup of overdose deaths involving illicit drugs like cocaine and heroin were the highest over the same period.

The Athens Banner-Herald reports (http://bit.ly/1oiXq0P ) overdose deaths were classified as being prescription only, illicit drugs only and a combination of prescription and illicit drugs.

There were a total of 630 overdose deaths last year. In 2010, the agency handled 729 cases. Deaths involving illicit drugs rose to 106 last year, up from 94 in 2012.

The GBI analysis didn't include autopsies performed by agencies in Cobb, DeKalb, Fulton, Gwinnett, Hall, Henry and Rockdale counties.