Hi Kevin,
The graph is correctly showing results for your analysis. You set up a parameteric analysis with a range of tilt angles between 0 and 20 degrees, and azimuth values between 150 and 225 degrees. Here's one interpretation of the countour graph:
In the attached .zsam file, I added a second case with a wider range of tilt and azimuth values so you can more clearly see which values maximize total annual output over the full range of possible values.
Does that address your concern?
Best regards,
Paul.