AutoCADder

Is AutoCAD 2009 a "major" or "minor" version?

There are discussions whether AutoCAD 2000i, 2005 or 2009 are really full new versions or just smaller updates, whether the odd versions are better or worse than the even ones (a popular urban legend).

I have used the AutoCAD commands database on the CADforum web site to compare the number of new commands introduced in the individual AutoCAD versions. These numbers differ a lot - especially see the glitch in the chart of AutoCAD 2000 and 2000i (combined) new commands. But the sheer number of commands can hardly express the scope of changes done in the specific version of the software. E.g. a change in DWG file format or a new rendering engine is definitely a major change but it might not be expressed in adding any new commands.