If you take unknown to mean Linux(which I do Linux Users have got to be the most secretive bunch on earth and all the others are self reporting) then Linux is at %9 If you include ChromeOs (which I half do) Linux is at %11.25 If you include MacOS(which I 1/4 Do) Linux is at %26.7 If you include windows(It technically has WSL So I 1/8 Do) Linux is At %100

Is this a joke yea. But technically you can write a Linux Program That will Run on every system without recompiling and you can’t say that about anything else so technically It has %100 available to everyone on earth(Except FreeBSD users Fuck them)