2.9 promille once (so 0.29%).
ppt is the english version of what you call "promille" but that unit (parts per thousand) is used more for analyses of air quality than for blood alcohol content. For blood alcohol we use percent.
Mine has only been measured twice. Both times I was was way drunk, and I'm sure my alcohol content far exceeded the 1.0% legal limit, but both times the officer didn't have the portable unit in the back of his car, so I had a ~15 minute ride, cuffed, in the back seat of the squad car to hyperventilate profusely. Both times I was able to pull of a measurement of around 0.6% or something like that. Low enough so that I didn't have to get a drunk driving ticket, which I understand is very, very expensive. Once the officer made notes of the fact that I was hyperventilating profusely and the local prosecuting attorney decided to make a stink about it. I had to hire an attorney to get me out of it, but it was still far cheaper than a drunk driving conviction would have been.
