Made the Twitter post type graph look less dramatically

Hi,

I recently wondered about the Post Types Graph from Twitter plugin. 

![thinkup](https://f.cloud.github.com/assets/203902/36625/cfbdd488-5356-11e2-82a8-622868334a81.png)

This made me feel like I'm an incredible broadcaster at Twitter. I think the graph should show some more relationship to what you really tweeted about. Just added 2 lines more for the Google graph.

Tested on my machine and looks pretty much more what I was looking for:

![thinkup-posttypes2](https://f.cloud.github.com/assets/203902/36629/4cf6f84e-5357-11e2-9c95-ff78b2fb306a.png)

Greetings!