In WWDC 2017, Cook compares iOS 10 penetration with Android 7.0 Nougat. In its keynote, Cook calls iOS 10 already installed in more than 86% of iPhone on the market.
Then Cook also compares it with the Android 7.0 Nougat penetration, which is only used in less than 10% of Android devices on the market, exactly 7%, as quoted from Talkandroid.
He also mocked Google who could not catch Apple on the availability of the latest OS for old devices. This topic is almost always raised Cook in every keynote opening WWDC.
The latest iOS and Android presence actually takes place in about the same time. Therefore, this comparison is actually still reasonable.
But the difference is, Apple worked on its own aspects of hardware and software for the iPhone. While Google is only working on the software side of Android -except in the line of Pixel phones.
As a result of the latest Android availability on Android phones that already exist in the market is not only dependent on Google, but also on vendors that produce Android devices.