Yeah man that’s how statistics work. It’s not a census. The people behind statscounter make calculations and approximations based on the data they get from they trackers. I think they know that there are people with tracking-blockers. And not only on windows.
They don’t just present simple numbers they get. They polish them and that’s literally their job.
Go into your wallpaper and style settings, tap on basic colours, pick one of 'em