From the manual:
"Median AR - Annual return by Monte Carlo analysis at 50% confidence level."

Higher is better, you make more money.

I'm mostly interested in the 95%-100% confidence levels, as you want to be prepared for the worst case scenario (which, by the way, can be worse than the 100% confidence level).

That's all I have to say in this context. At least make sure you have good risk management.