A new (increased) version number indicates new features, whereas the revision number relates to Hot- and Bugfixes within a certain Version. Therefore, these last two numbers will change more frequently due to the meaning.
For example the {{UBIK}} Version 2.4.4.1, which is major Major = 2, minor Minor = 4, version Version = 4 and revision Revision = 1, implements additional features if compared the {{UBIK}} Version 2.4.3.1.
But {{UBIK}} Version 2.4.4.3 has the same features but includes certain hot- and bugfixes.