NONE; 99.99999999999999999999999999999998% is as close as I come. Why? Because that is how science and open systems work. Nothing is certain; all things are subject to change. I also say I have faith in; as in trust; science and the knowledge from science. I cant KNOW something; because can you KNOW a thing that is not true? IMO, no, you believe a thing that si not true. Since I dont know if something is true, but only very strongly suspect it to be true, I avoid saying I know anything.

There are problems with this kinda honest thinking and speech. First, people who want to say faith requires you to not have evidence; no; I can invest faith based on evidence or anything I want. It doesnt require gods. The second part is that this kinda non-committal speech is not great at convincing people that something is likely to be true. And it really brings out the nutjobs that treat science as what people traditionally call religion. They dont understand the science behind something and will fight like Christians to support a view they dont understand just because science seems to say one thing or another. I'm old enought to have seen some science change and needle people IRL who have taken such crappy religious positions.