Brent Ozar has a breakdown of SQL Server adoption by version:
Ever wonder how fast people are adopting new versions of SQL Server, or what’s “normal” out there for SQL Server adoption rates, hardware sizes, or numbers of databases? Let’s find out in the summer 2020 version of our SQL ConstantCare® population report.
Out of the 3,650 servers sending in data recently, the most popular version of SQL Server is still 2016.
It’s an interesting survey, but it’s important to remember with any survey what the biases are before drawing conclusions on the general population of all SQL Server instances. This is among ConstantCare users, so if I had a hunch about them, I’d say they’re going to blow out the middle versus gen pop—in other words, I’d expect 2019 and 2017 usage to be a bit higher across the world (and not just among ConstantCare users), but also 2005 (not pictured), 2008, and 2008 R2 to be higher. My hunch here is that the former are shops which have their act together and figure that they don’t need ConstantCare, and the latter are all of those “hidden” instances of SQL Server acting as the back end for small business websites and the like, where nobody even thinks about having a database administrator, much less paying for tooling. Nonetheless, these are interesting trends and even if I think the general population might look different, my data-less guess is that these numbers look reasonable.