I just saw on 2K's official site (https://store.2k.com/en/civilization) that "Sid Meier's Civilization is one of the most influential and successful strategy franchises in video game history, having sold more than 51 million units worldwide." While on Feb. 28th, 2016 (Civ 6 was published in Oct. 2016), the sales figure of civ franchise was 33 million, with 8 million belonging to civ 5. Source: https://venturebeat.com/2016/02/18/...sions-33m-copies-sold-1-billion-hours-played/. Apparently, 18 million more copies were sold during this time. Some of them definitely belong to civ 5. What's the share of civ 6 sales? 10 million?