bug 914385 - extend explosive graphs to occupy a whole row

Before:
![screen shot 2013-09-09 at 3 49 38 pm](https://f.cloud.github.com/assets/21467/1111133/28a5d778-19a2-11e3-89e7-d0434568a1ec.png)

After:
![screen shot 2013-09-09 at 3 29 17 pm](https://f.cloud.github.com/assets/21467/1111126/0e0905ac-19a2-11e3-8c65-4e1df4532bd4.png)