"On average I get at least 1 lvl 100 per 2 80 stam runs, sometimes more but not often less then that."

I guess the RNG just hates me. On average I get 1 lvl 100 per day of 80 stam runs.

I have also had a few days like that, it seems to even out in the end with those days I've gotten 6 or more with only 5 runs.
What can I say? RNGesus is NRGesus and if you don't pray hard enough you won't get results.