Apple has updated its App Store distribution page to note 66% of devices are now running iOS 9, based on App Store usage as of November 2, 2015. When iOS 9 was released back in mid-September, it took just over three weeks for 57% of devices to update.

After the initial upgrade to iOS 9, new features allow future updates to be installed easier, such as the ability for delayed automatic installs in the middle of the night, plus temporary deletion and reinstallation of apps to make space for updates.

Last year, it took until the first week of January for 68% of devices to adopt iOS 8, so for now, it looks like iOS 9 is off to a blistering start.