The latest stable version is 11.05r2, the one you have.
The latest beta version, at this time, is 11.10b3. So if you don't allow beta updates, you will have 11.05r2 maximum.
Beware, beta versions are recommended for users who don't mind encountering bugs. We often test beta updates on a second copy of X-plane, in order to give feedback and help Laminar Research release the next stable version.