Unfortunately @vincent is right. Based on https://www.w3counter.com/globalstats.php?year=2016&month=8 stats for August 2016, IE+Edge still has ~10% of market share in browsing web - both entertainment and professional purposes.
Knowing that IE has ~5% share, the rest are both Edge and other even more outdated versions of IE that don't support some of the advanced stuff you can do with Webflow.
Following report shows how IE is slowly dying, but it's not dead yet.
It's also nicely visible when new Windows was out But it also show that after every upgrade/update, IE is less and less noticeable, but it's still there. It's still ~10% of all browsers (summing up all IEs+Edge).
My post was salty and humorous, because as most of you guys I also had to deal with clients that say "Why this website doesn't look good on my 10 years old laptop?" and I truly understand how frustrating this could be. Yes - it's easy to write a modal that will ask user nicely to update to a modern browser that supports everything, but some/most companies do not allow of installing any software within the company that is not authorized by sysadmin.
IE is easy to configure remotely for computers that are within workgroups. It's also easy to strict access for IE for entire company with few clicks of sysadmin's mouse! This is why IE is commonly used as a main browser for companies.
It's also something people are simply used to... I didn't give up Netscape Navigator until it was practically dead and didn't support 80% of the stuff. Ba! If NN was still up to date I wouldn't use Chrome! But there are things that we should follow along, and things that we simply can't force push on users.
So yeah... IE sucks, but we have to deal with it for the time being.