https://www.theverge.com/2018/10/11/17965302/ios-12-install-adoption-progress-ios11

Apple has just released the first numbers for iOS 12’s adoption rate on its App Store developer portal, and things are looking up from last year’s iOS 11, with Apple’s latest mobile OS hitting 50 percent adoption across eligible devices in 23 days (via VentureBeat).

For comparison, iOS 11, released on September 19th, 2017, didn’t hit 52 percent adoption until November 6th of that year, taking 48 days, or over twice as long as it took iOS 12 to hit its own 50 percent mark. Apple’s portal also notes that adoption rates are even higher for devices released in the last four years, which hit 53 percent adoption of iOS 12.