Put some C# on Github!
Read GitHub language trends and the fragmenting landscape.
Here's a quote from that article:
Both C# and Objective-C are unsurprisingly almost invisible, because they’re both ecosystems that either don’t encourage or actively discourage open-source code
I don't know if I could agree that either are being "actively discourage[d]" (certainly Jeremy Miller has some thoughts on the matter).
BUT, what I want to tell you today is: put your C# code on to GitHub today! Even if you don't think it's very good, it might help someone, it might help you get some more experience with git and GitHub, and it will certainly help bump up that C# graph.