Have a look at the two "Vulnerabilities by Severity over Time" graphics from a modified Executive Report template. They were generated at the same time, over the same asset group. The only difference between the report templates is that the first (top) report had the Filter set to New, Active and Re-Opened status only. The second (bottom) report included all the above plus Fixed status.
Obviously, these two graphics paint a very different picture of the effectiveness of our patching activities. But which one is right? And why are they different?