Rental vacancies per county/town/neighborhood?

[Junbin Teng]

Does anyone have a recommendation for private/government statistics which have rental vacancies rate broken down by county, town or even neighborhood?

I'm asking because from a few hours of googling around, it seems like the numbers across website are wildly different (I've seen from ~5% to 10% for the same exact zipcode), and I'm wondering which ones the veterans trust?