From what I see, Kemper is using the usual versioning. So no one knows how many releases of OS 9.x we will get.
So, just for the understanding. A usual software versioning (it's called semantic versioning) looks something like this:
For example: If everything is fine after 9.1.1, we could already get 10.0 as the next version and no 9.2, 9.3 or more...
So it could be something like
Major version: Major new features
Minor version: Minor new features or changes to behaviour
Revision number: bug fixes
(The above obviously doesn't take into account stuff that is not customer-oriented, like refactoring of code etc)