iOS 9 keeps chugging along, with an increasing number of iPhone and iPad users adopting the latest version of Apple's mobile operating system. Apple's latest numbers show that iOS 9 is now installed on 66%, climbing 5% in two weeks.

Just about this time a year ago, iOS 8 had been installed on 52% of iOS devices, with that system now holding a 25% share. Older versions, from iOS 7 on down, now stand at 9%.

Not only is Apple continuing to sell new iPhones with iOS 9 or later pre-installed, but many users have most likely found it much easier to update to the new system thanks to more relaxed requirements on system storage. Additionally, Apple recently released iOS 9.1, which added, among other things, new emoji characters, which often prove to be a driving force in getting people to upgrade quickly.

Source: Apple