Missing link
The data from US government websites. the high percentage of IOS indicates how skewed the set is:
https://analytics.usa.gov
Akamai also provides worldwide numbers: https://www.akamai.com/de/de/solutions/intelligent-platform/visualizing-akamai/internet-observatory/internet-observatory-explore-data.jsp
El Reg routinely ignores this resource. It has MS Edge, which is a reasonable proxy for Windows 10, at around 6 %
Biting the hand that feeds IT
