Don't know about the US government specifically however it's not uncommon for the government to be the biggest single user of it's websites, followed usually by business/corporate users. If this is the case in the US also then a lot of business users have not upgraded to Windows 10 yet.

Hey dogma1138, I manage this program. Only about 4% of total traffic is from within US gov networks.

The US Postal Services' websites are by far the most visited.

Followed by things like the Weather services and then things related to health or social security.

Those are "costumer"-oriented sites. But then again, some of them could be browsing from their work computers.

That doesn't necessarily mean much, every time I went to the post office here in the UK and asked for something specific they went on their website and printed a page for me (not the most efficient use of resources but hey it works), there's also the case of terminals at public government offices where the public can go to use online resources (home office, and job center are a good example of that), this could be not that different from 30% of the site hits for HSBC in the UK which are from within the internet banking terminals in the branches.

But as tdlowden said apparently only 4% actually comes from US government networks so I guess it's not the case, tho I don't know if it's only federal or also local government since the US has a very tiered form of government.

I found it interesting as well that more people seem to be using IE 7 vs 9 or 10.

It's because 9 + 10 auto-upgrade to 11 unless you turn it off in automatic updates.