Curious to see what dark hole you pulled those numbers out of.
Here is reality: Success rates from the client exp file (circa 2012 - may have been changed since trinity)
+1 = 95%
+2 = 85%
+3 = 76%
+4 = 69%
+5 = 55%
+6 = 27% <-- Note big drop in success here
+7 = 64%
+8 = 53%
+9 = 46%
+10 = 12% <-- Note big drop in success here
+11 = 52%
+12 = 40%
+13 = 35%
+14 = 24% <-- Save your pres stone money after this point
+15 = 1.7%
+16 = 1.1%
+17 = 0.6%
+18 = 0.4%
+19 = 0.2.%
+20 = 0.01%
+21 = .04%
+22 = .02%
+23 = .01%
+24 = .006%
+25 = .003%
+26 = .0007%
+27 = .0003%
+28 = .0001%
+29 = .00005%
+30 = .00002%
+31 = .00001%
Those are raw base success rates as known by the client and the server via synchronized files (I've converted the raw 0-1,000,000 values to simple percentages for you)
These do not take into consideration effects of:
1. Delta boost rates applied on a per-server basis (different sets of deltas allows GMs to run events and such). There will always be a 'normal' delta.
2. Reinforce Supporter guild buff
3. Abradant grades (these are supposed to increase success rates, but I have yet to see any evidence of that)