Who of you guys are on an "Unknown" OS?

I've been wondering how many Linux users are being listed as unknown by statcounter out of curiosity. There has been a big global bump "Unknown".

Obvious ones are UserAgent spoofers Vpn users but I feel like that's pretty niche. I'm wondering if SteamOS, Endeavour and BSD show up as Unknown. Furthermore, will just all non-Ubuntu based OS?