What is supposed to be the intended base deconstruction percentages for rune recovery? 25% each for recovery of 0,1,2, or 3 runes?

I waited to level enchanting when I heard they were patching it. I had 86 white runes in the bank, all splendid and monumental level. I leveled enchanting starting at lvl 22 with the following skill point distribution (top down): 3/4, 5/9, 1/3, 2/3, 2,3

I believe that last one is the issue, runestone extraction. At 2/3, it supposed to be increasing extraction of each type by 6%.

I started recording when after the first 12 deconstructs I had not received a single rune, though I was gaining experience for it. At the end I'm level 27, almost 28, but 54 times I did not receive any runestones. 54/86 = 63% of the time? I don't see how this is really possible. I have exactly 80 runes. in my inventory, which means that somewhere around 20+ times I recovered all 3 runes.

So this doesn't make sense to me. Ultimately I ended up with less runes than the guaranteed 1 per as it was before, although I advanced 5 levels where before I maybe would have advanced 2.

Can someone from ZOS explain if this is right or am I seeing a bug. I think it's a bug. That's way too many 0 drops.