I'm trying to dig out the info, but I'm pretty sure the devs have stated that RE chance is modified by your level of crafting skill VS the item's actual level. Which means that you simply wouldn't have enough info to claim anything at all, since we don't know how the initial 20% base rating would be affected.
For all we know, you could be at 20% base - 5% mod. Meaning your 14ish% would be right within target.
I'll post link of the Dev post ASAP.
I don't know for certain...but I feel
like this is a statement I could believe. Whenever I RE a green item on par with my crafting skill level, it takes a lot of RE'ing to get the blue item....but if I RE an item very far below my current skill level, I only have to RE a couple or three at most to get the blue item. This would suggest a curvature in the RE possibility function being used as it relates to crafting skill level.
Which would explain why it's so difficult to obtain blue/purple endgame crafting schematics from RE.