Ignition interlock systems in cars have prevented 1.77 million attempts at drunk driving since 1999, according to a new report by Mothers Against Drunk Driving (MADD).

The report, released Wednesday, is based on data from the 11 major manufacturers of ignition interlock systems, the Associated Press reports.

Ignition interlock devices are wired into vehicles. A person convicted of drunk driving must blow into the device to determine their blood alcohol concentration. The device has a preset level for blood alcohol concentration. If a person blows into it when they are over the set limit, the vehicle will not start.

The report found ignition interlocks have prevented 1.77 million attempts by a driver to drive with an illegal blood alcohol concentration of .08 or higher, which is legally considered drunk driving in all states.

The system sends a signal back to the manufacturer with the results, which allows them to keep track of how many times the devices stop attempts at drunk driving, the article notes.

According to MADD, 25 states have laws that require ignition interlocks for anyone convicted of a drunk driving offense. All states have some type of ignition interlock law, but some require them only for certain levels of offenses and blood alcohol levels, or allow judges discretion.

“In the 25 states that don’t have all-offender ignition interlock laws, MADD calls on legislators to pass these lifesaving laws this year,” the organization stated in a news release.

The National Transportation Safety Board recommends that states require mandatory ignition interlock devices for first-time drunk driving offenders.

A study published in 2015 concluded that if all new cars had devices that prevent drunk drivers from starting the engine, an estimated 85 percent of alcohol-related deaths could be prevented in the United States.