According to the dedicated distribution section of Apple’s support page, a whole lot of 87% of all active iOS devices worldwide were running iOS 10, Apple’s latest official version of the operating system, as of July 28, 2017.
That’s merely a month and so before iOS 11 hits us, and it is quite likely that it will enjoy a wide adoption merely after a week or so after Apple releases it. Around 9% of Apple’s devices are running iOS 9.
Furthermore, around 3% of all devices are powered by an earlier version of the operating system.
