New York ? A new report says bicyclist death rates for children have fallen dramatically in recent decades, but have risen sharply for middle-aged men.

Experts believe the statistics reflect that adults are biking more and kids are biking less. The biggest rise was for men ages 35 to 54.

The Centers for Disease Control and Prevention released the numbers Thursday. The agency looked at bicyclists killed on public roads in collisions involving motor vehicles, so not every biking death was included.

During any given trip, bicyclists were twice as likely to die on U.S. roads as people riding in motor vehicles. Still, bicyclist death rates were low — overall about 0.2 cyclist deaths per 100,000 people in 2012, down from 0.4 in 1975.