So much in this chart was just plain wrong. I guess they checked how many people have a mount. Since the Sha was bugged for a long time and did not drop any mount it's normal that only very few people have it. But the drop rate was fixed. The mount with the lowest drop rate and hardest to get is the Big Love Rocket since you only have limited tries for a few days every year and the drop rate is 0.03%. For a 90% dropchance, you need 7674 kills. Love is in the Air lasts for 2 weeks, so that's 14 attempts pr toon pr year.