Here's a spreadsheet with the number of reported cases per 1000 population by county as of today.

There are a million variables and unknowns, such as rate of testing, availability of testing, reporting protocols, etc., so not sure if this means anything. Maybe somebody who knows something about statistics can comment.

Anyway, the numbers seem to be about what you would expect. Davidson and surrounding counties have higher reported rates. Knox County is surprisingly low. Counties around Clarksville appear to have higher rates but Montgomery County is relatively lower. Robertson County appears to be an outlier. For reference, the statewide number is 0.09. It's curious that only 52 counties (thankfully!) out of 95 have reported cases.

Sources: Cases, Population