UNA version in back-up files

Hello, all you dear Unitarians. Can anyone tell me how to find the UNA version in the back-up files of one's site? Years ago, I remember in Dolphin how we would manually change it after each update. :)

I have supposedly modified some files and therefore cannot update to the next version, you see. So I need to find what version my back-ups are. Yes, I am aware that a global forced overwrite is possible but I would prefer not to employ that method.

Thank YOU.