LOS ANGELES — Motorcycle fatalities on U.S. roadways dropped dramatically in 2013 for the first time since 2009.

It’s only the second time annual deaths have fallen since 1997. But as automobile deaths continue to fall, with better safety features in cars, motorcycle fatalities for 2013 accounted for a growing share of all traffic deaths – 14 percent, up from 9 percent a decade ago.

The National Highway Safety Transportation Administration takes a year to compile and release its annual survey of accident data, so the 2013 figures are the latest available.

The survey said 4,668 motorcyclists lost their lives on U.S. roads in 2013, down from 4,986 in 2012, a 6.4 percent decrease.

That compares with a 3.1 percent decrease in all U.S. traffic fatalities.

Fewer motorcyclists died in states with helmet laws — by a wide margin. In states without helmet laws, 1,704 riders lost their lives while riding without a helmet, compared with 150 in states with helmet laws, the report said.

Older motorcyclists, who increasingly make up the largest cohort of motorcycle riders, also scored significant improvements in safety.

The 50-to-69-year-old riders showed a 60 percent decrease in motorcycle fatalities from 2012 to 2013. The NHTSA report said 32,719 people died in traffic accidents in 2013, down from 33,782 in 2012.