It passed 1% by market research companies. It actually passed 1% a long time ago and is actually around 2-4% for the desktop market. MacOS and Linux have about the same market share. The reason why Linux is so much lower is because not all Linux installs hit all the sites that the researchers monitor.
For example, I have 4 computers, all running Linux. Only 1 of them I use to browse the internet with and another one isn't connected to any network. So, even though I have 4 installs, because only one of them I use to surf the web, I'm counted as having only 1 Linux install.