No.
Atlassian do gather numbers on support calls, but this is not going to be representative of all the installations out there. You can't rely on licences because a licence is either valid up to 3.13, or it's valid from 4.0 to the latest version, so you can't even say "we've got X licences on version Y" - all you know is that your users are on 4+.
The question is also a bit difficult because your counting might be different. Of the top of my head, I can compare two sites I've worked with recently - one with 10,000 users but 1 JIRA, and the other has around 20 JIRA installs, but a total of 200 users. Does the large site mean you'd prefer to target them or are you aiming at small user bases?
That said, most people try to keep their systems up-to date, and I'd think it's safe to say that you're looking at over 80% being on JIRA 6+. There are people on 3.x, some on 4, and more on 5. But I'd simply code for 6+. It gets more difficult if you're using features in 6.3 that aren't in 6.2 or have changed since then, but you can worry about that when you run into it.
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.