How to represent a score that can be positive or negative?

I need a simple (aka not ugly) visual element to represent a score that can be positive or negative.

My score matrix will probably be similar to this page: http://snapsort.com/cameras/Canon-PowerShot-G9-X-Mark-II-score

But I need to allow for negative scores.

The red to green bar graph (red = 0, green = 100) in the example above does not work when there is also a possible -100 value.