Tesla’s crash rate dropped 40 percent after the electric carmaker installed its semi-autonomous Autopilot software, government regulators reported today.

The National Highway Traffic Safety Administration just released its report on the May 2016 fatal accident involving a Tesla Model S. Within the document, the government reports that the number of crashes dropped dramatically after Tesla introduced Autopilot in 2015, a fact that would seem to bolster the company’s claims about the safety of semi-autonomous features in its vehicles.

Report highlight: “The data show that the Tesla vehicles crash rate dropped by almost 40 percent after Autosteer installation.” — Elon Musk (@elonmusk) January 19, 2017

NHTSA analyzed all mileage and airbag deployment data supplied by Tesla for all 2014 through 2016 Model S and 2016 Model X vehicles equipped with Autopilot. The data show that the Tesla vehicles crash rate dropped by almost 40 percent after Autosteer installation.

The government concluded that while advanced driver assist systems (ADAS) like Autopilot may help in reducing auto accidents, they should not supplement or replace a driver’s attention to the road. “While ADAS technologies are continually improving in performance in larger percentages of crash types, a driver should never wait for automatic braking to occur when a collision threat is perceived,” the NHTSA said.