Five percent is very much non-zero and scarily so. And this is just for the vehicle occupants, not counting damage and injury to other people hit by a vehicle. Whilst we can applaud the work done, there is much more to do.
http://www.ejectionsite.com/stapp.htm
The problem is that passenger vehicle restraints suck because they have to fit anybody and everybody and simple enough that you actually use them. In the upper classes of racing it's not uncommon for someone to walk away with only a concussion after a barrel roll down the infield but they have better seats and harnesses. Even a 4pt harness like found in a go-cart or small aircraft would be a massive step up.
I'm not disputing that we can make very safe vehicles, just look at F1 drivers walking away from 300kmph crashes, but they shed so much energy to tires, tire barriers, gravel and all the other stuff that slow them down.
Regarding injury from being hit by a vehicle: that isn't the point of this release by Tesla. The focus is the safety of the occupants, which is far more top of mind to buyers than the worry of hitting pedestrians. It's great that many brands now have CV that can detect and stop based on a person being within the vector of a vehicle. Tesla happens to be one of them and it would be interesting to see an objective test of pedestrian detection and mitigation at some point. Probably a critical test for manufacturers to have to pass as we continue towards autonomous operation.