What’s tricky is figuring out the appropriate human baseline, since human drivers don’t necessarily report every crash.

Also, I think it's worth discussing whether to include in the baseline certain driver assistance technologies, like automated braking, blind spot warnings, other warnings/visualizations of surrounding objects, cars, bikes, or pedestrians, etc. Throw in other things like traction control, antilock brakes, etc.

There are ways to make human driving safer without fully automating the driving, so it may not be appropriate to compare fully automated driving with fully manual driving. Hybrid approaches might be safer today, but we don't have the data to actually analyze that, as far as I can tell.