DENVER, Colorado — The number of passengers who died in car wrecks in which they were not wearing seat belts hit an all-time low in 2007, the Colorado State Patrol says.

Last year, 206 people not wearing seat belts were killed in crashes out a total of 389 drivers and passengers who died. The percentage of unrestrained motorists killed was also the lowest on record at 53 percent.

In 2002, the first year of a stricter program of seat-belt enforcement in Colorado, 383 people died unbuckled, representing 66 percent of the total number of drivers and passengers killed.

Not wearing seat-belts is a more serious problem at night, officials say. In Colorado last year, seven out of 10 people killed at night were not wearing seat belts, compared to less than half of those killed during the daytime.

Authorities are also focusing on teens. Although the number of Colorado teens killed in traffic crashes dropped 34 percent in 2007 from 2006, of the 45 teen drivers and passengers killed in Colorado in 2007, 28 — or 62 percent — were not wearing seat belts.