
In short XP is growing again.
This might mean that old software needs XP and people will keep that as long as they can. It might also mean that the Windows alternatives Microsoft has produced are not to the customers liking.
Windows 10 will be free for everyone with Windows 7 or newer so the XP people need to pay for Windows 10 too. That might further motivate them to hang on to Windows XP.
It lives and thrives well in my VB too - and I have no plans of upgrading it.
Nevertheless this is surprising.