Apple's latest App Store distribution numbers show that iOS 8 has now been installed on 72% of all compatible devices as of Feb. 2, 2015. iOS 7 now stands at 25%, with all the older versions claiming a total of 3% of installs.
While the new stats represent a 4% gain compared to the iOS 8 adoption numbers from January 7, 2015, they are still behind the installs of iOS 7 at this same time a year ago, when it claimed 85% of all compatible devices. Clearly some iPhone and iPad owners have yet to make the change to iOS 8, although there could be several reasons for that decision.
iOS 8 launched in September 2014, so getting a 72% adoption rate in about five months is still pretty solid. By contrast, Android 5.0 Lollipop has only been installed in 1.6% of all Android devices since it launched in November 2014.