I've always been a sucker for data, maybe it's why I like contributing to this wiki.
However, I was just browsing Steam Charts and saw a total playing time of 153,000 hours into Kenshi which puts it just below Star Wars, Knights of the Old Republic (240,00), Assassin's Creed Unity (220,00), and Hotline Miami 2: Wrong Number (193,000) by comparison. The closest game to Kenshi is Alien: Isolation (167,000). Not that bad for a game whose all time peak was 981 players back in December 2013. Unsurprisingly, small rises in both average players and peak players happen with each stable build.
Hopefully we'll break the 1,000 player barrier with a full release by early-to-mid 2017.