In the pie chart (seen below) we can see it that iOS 11 is still on 39 per cent of devices, while earlier versions of the mobile devices sit at 11 per cent. In total, 50 percent of all iOS devices have made the jump to iOS 12.
Apple senior vice president of software engineering Craig Federighi said of iOS 12 at a developers conference earlier this year the new system offers "detailed information and tools" to help users and parents keep tabs on device use.
The dip in the install base of iOS 11 was also pointed out in the Mixpanel data reported last week that showed iOS 12 being present on 47.56 percent of active Apple devices, while iOS 11 was available on 45.58 percent of active devices. This adoption rate is comparatively higher when compared to iOS 11.
With the newest iOS 12, Apple has aimed at improving performance and stability, leading to more users actually willing to update. In short, 89% of all iOS devices are now running an iteration of iOS that, at the most, is about 1-year-old. People have started reporting issues with the Wi-Fi as it doesn't connect or sometimes doesn't works and it's ironic since Apple released the iOS 12.0.1 with bug fix to resolve Wi-Fi issue where it used to switch from faster 5GHz bandwidth to slower 2.4GHz bandwidth.
iOS 10: 54% as of October 11, 2016. The new version that has features such as Screen Time and Siri Shortcuts that have attracted a large number of existing Apple device users.