The way "average" works is that you average over something - a population or set. It is very important to be clear about what that something is and whether it's appropriate.
Why do you believe that Autopilot outperforms humans in comparable conditions? If this is based on Tesla marketing, I'm extremely prejudiced against them, and assume out of hand that they simply aren't making the right comparison and don't care. However, if you think that is incorrect, you could elaborate on why you have the opinion you do.