I think you should look at 1-5 or 1-10 scales logarithmically. It doesn't take a whole lot of work to become basically competent in a git or Rails (2/5), but to

I think you should look at 1-5 or 1-10 scales logarithmically. It doesn't take a whole lot of work to become basically competent in a git or Rails (2/5), but to become an expert (4/5) takes exponentially more work.