As of late 2017, Google/Waymo had recorded just 4 million miles of real-world self-driving in its entire history: https://techcrunch.com/2017/11/27/waymo-racks-up-4-million-s...

NHTSA data measures number of fatalities by the hundreds of millions of miles driven -- the latest rate being 1.18 fatalities per 100 million miles: https://www.nhtsa.gov/press-releases/usdot-releases-2016-fat...