iOS 10 is officially out since September 13. And today, Apple has yet another reason to celebrate - their software is already used by 66% of all Apple devices.
We can consider it a groundbreaking achievement, when comparing it to past iOS updates. iOS 10 is a hit. No other iOS had such an impact on Apple devices in such short time period.
It has started rather slowly, as in first two weeks iOS 10 was behind results of for example iOS 6, 7 and 9.
iOS 10.0.2, which came out on September 23 have surely contributed to this success.