I have a question about test positivity rate. UW Virology has been at about 8%, and that's them soliciting tests from all over the nation over the last week dur

I have a question about test positivity rate. UW Virology has been at about 8%, and that's them soliciting tests from all over the nation over the last week during a time when testing was very constrained. Even then, UW only reached capacity yesterday, they had capacity to spare until then. Divide worldometers "cases per day" stat by the the CDC website testing data as of a few days ago (the most recent day they declare their numbers complete), and you get around 8%. Finally, the Friday press conference mentioned the LabQuest LabCorp tests coming online and adding significant capacity, and that their test positivity rate as of then was about 2%, and this is all during a time when testing is limited, and presumably, only the most urgent or probable cases are being sent off for testing. I don't have a lot of exponential-math insight, but those rates seem low if the virus has spread like crazy already. How does that reconcile with the math in this article?