Apple just rolled out its newly updated usage statistics and it notes that 76% of the iOS device users have iOS 10 installed on their devices while 18% of the users still use iOS 9.
Apple has also stated earlier that iOS 10 had the highest adoption rate in their history of OS releases.
The graph chart shown by Apple still notes 6% of the devices running iOS 8 or older. Most of these devices are those that cannot update to iOS 10.
Have you updated to iOS 10?