OK, quick show of hands. How many people are still on i5/OS 5.4 or below? Don't worry, nobody can see you. No embarrassment other than what you put on yourself. OK, that's fine, thank you.
If you are just putting your hand down, don't feel too bad. A lot of good shops are still on some version of 5. Shoot, I even know someone who is on 4.3, although I certainly wouldn't acknowledge them in public. But don't feel too good either, because there are a lot of people who have already moved up to 6.1 or 7.1. If you haven't, it's time to get moving.