The Colorado Sun: When the coronavirus pandemic besieged Colorado last spring, Boulder Mayor Sam Weaver and a few of his friends quickly developed a new hobby — downloading data on the virus’ spread in the state and plugging it into their own spreadsheets for analysis.

Weaver is an engineer by training; data is oxygen for him. He said having numbers for Boulder and other jurisdictions at his fingertips provided fast insight into the pandemic. Where was it spreading? Where was it in decline? What could his city do differently?

But there was one measurement where Weaver and his friends soon noticed something curious: Test positivity. The figure, expressed as a percentage, shows how many coronavirus tests in a given area are coming back positive. Generally, anything below 5% shows that the virus is under control, according to the World Health Organization. Currently, CDPHE says the positivity rate over the past week in Colorado is 8.1%.

Visit The Colorado Sun for more.