I manage 134 branded sites for a university and a handful of other sites. We target IE11, Edge, Safari, FireFox and Chrome compatibility with desktop and mobile (ios, android). Once Microsoft announced sunsetting support for earlier browser versions our job got a lot easier. We all said "thanks MS, took you long enough".

In the last 30 days for the branded sites we have roughly these percentages of sessions by browser:

  chrome  46%
  safari  32% 
  ie      11%
  firefox 8%
  edge    2%

This for about 370,000 sessions.

We will continue to support the same browsers for the next two to three years and then adjust as needed.