I'm fairly certain only a single person has ever properly achieved WC without cheating (e.g., mission exploit or achievement unlocker), and that's DDRJake. The most passionate fans are also the ones that participate in the online community, meaning if a WC was actually achieved by someone, it would almost certainly be posted on these forums or somewhere like reddit. Assuming EU4 sold 50,000, which I say would be a healthy estimate, that would mean WC has a real achievement rate of 0.002%. This is technically the lowest it can possibly be besides 0.0%.