DETROIT (AP) — More than 800 rear-seat passengers who weren’t wearing seat belts were killed last year in U.S. traffic crashes, and a highway safety group says states aren’t making enough progress in getting people to buckle up.

The Governors Highway Safety Association says in a report released Monday that more than 400 of the 803 people who died would have survived if they were belted.

The association put out a report in 2015 drawing attention to rear seat-belt use. But it says that since then, only two more states have enacted rear seat-belt laws.

The group, which represents state highway safety offices, says 20 states still don’t have laws requiring rear belt use. Of the 30 states with laws, it’s not a primary offense in 11 states, meaning that police can’t stop a car if rear-seat passengers are unbelted.