That's a list of which GLSL version was released with what version of OpenGL.
The numbers declared in the files, such as 150 and 330 is the first and second part of the GLSL version number without the period (.) if I'm not mistaken.
Use an as new version as you can.
Edit: http://renderingpipeline.com/2012/03/shader-model-and-glsl-versions/ Another list with thier respective version numbers.