version of VS in csproj file

Long ago, I need to determine the Visual Studio version of a csproj file:
csproj is an xml file and the content is something similar as follows:

  
    Debug
    AnyCPU
    9.0.21022

If you don’t have got .sln file, examining the csproj is a way to determine where the project is structured.

Product Name Product Version File Format
Visual Studio .Net v7.0 7
Visual Studio .Net 2003 v7.1 8
Visual Studio 2005 v8.0 9
Visual Studio 2008 v9.0 10
Visual Studio 2010 v10.0 11

So for the above csproj, the version of VS is 2008.