I'm actually in exactly the same position as you (albeit only at my job for a year rather than longer). I've block stuttered since I was around 15. It was worse then and now I've reached a stage where I have so many techniques and substitute words to get by and I don't think that many people know I stutter in general. Sometimes it's clear that I have a random pause before saying something but it's never long enough to feel weird and was definitely a lot worse when I was younger. I'd actually say I wouldn't tell anyone about it. While people will still be respectful, I'd still feel like they'd see me in a different way (naturally and through no fault of their own). They'd always think of my stutter when they talk to me and I wouldn't want that to be going through their minds. If you can get by and no one has realised I don't see a reason to tell them. The only person I told was my manager (who was really supportive and understanding) and funnily enough I stutter more around him and I sense he notices it a lot more too.