I said 70-80%, but honestly that's probably just me being pessimistic.
I'm really paranoid. And since I do still get stared at by people, and people are constantly treating me, well, a little bit too nice for lack of a better term, I find it hard to believe that I'm not tipping off some people's radars. I'm taller and larger-framed, so I think that fact alone probably has some people questioning the possibility that I might be trans. I think that's really where I'm at with a lot of people, is where I'm more than female enough where they can't see me any other way, and they'd never not gender me female or treat me like a woman, but at the same time maybe they're suspicious that I might be trans, they're not sure, they might go looking for confirmation, or it takes them a while and takes them some careful study to figure it out.
This is all speculation. I'm also constantly asked about whether I have a boyfriend or not, random guys have hit on me at work, people constantly ask me about "when I was a little girl," or about whether I'm a mom, or if I have a husband, etc, etc, things that you just wouldn't ask someone who was obviously trans.
So I'm probably stealth to most people, but just transy enough to make some more-observant people question the possibility.
(Also, some people at work do know I'm trans, but mostly because I didn't move far enough away from my old hometown, and I still work in the poker/casino industry, which is one where the same people are constantly going back and forth between different casinos depending on tournaments and where the action is on any given weekend, so I had no chance of being 100% stealth, I still see a lot of people who knew me pre-transition, and word traveled through the grapevine because people don't know how to keep their mouths shut, so yeah, although I'm probably not instantly read as trans by people, lots of people know simply because of other people I knew telling them.)
I'm okay with that for now, as long as those who are seeing me as trans are seeing me as a trans WOMAN, and not interpreting that as "a guy dressing up as a woman."