Sample is proabably too small to determine these stats, and WAY to small to determine any sort of win rate (need +100k hands).
Given that, pre-flop of 22% is decent maybe on the high side, but I don't think so, 50% flop fold is about right, but then you fold 66% (4% out of 6%) on the river which probably means you are folding too much on the river.
Better stats to look at are WSD% (went to show down) and W$SD (won $ at show down). WSD% should be around 30 and W$SD should be in the low to mid 50s, although it will depending on how you are running.
Remember it is important to show down in large pots, don't fold 20-1 river bets even if you think you are most likely beat.
While Miller says small stakes players go too far with hands, it is a generalization, so try to do what is right for each situation. Meaning don't think "oh bad players go too far with their hands, so I am going to be a good player and fold here and not make that mistake". Applying broad thought processes to the game is not going to be +EV.
Check out this link for more on stats:
Micro-Limit FAQ