Brent Ozar shares some percentages:
For the long story: ever wonder how fast people are adopting new versions of SQL Server, or what’s “normal” out there for SQL Server adoption rates? Let’s find out in the summer 2023 version of our SQL ConstantCare® population report.
Out of the thousands of monitored SQL Servers, a whopping 44% are SQL Server 2019! That’s the highest percentage we’ve seen for any version in the 3 years that we’ve been doing this analysis.
Standard statistical sampling rules apply, though there is an interesting note in the comments about how EC2 instances break down in AWS by version of SQL Server, and the numbers are reasonably similar.