https://www.phoronix.com/scan.php?page=news_item&px=Steam-Survey-February-2018
With the start of a new month comes a new batch of Steam Survey results from Valve... For February 2018 they are reporting a 0.28% marketshare.
The 0.28% is perhaps more believable than in previous months with the February numbers reporting just a 0.03% increase over January's figures. Originally the December numbers reported a 0.43% marketshare for Linux and lowered it to 0.26%. For the January numbers they then reported a 0.41% marketshare for Linux, only in mid-February to lower those that January count down to 0.25%.