Question about Section-8 and Rental increase request

[Elidania Ayala]

How do I go about finding information about comparable units to submit a rental increase request for my rental properties in Chicago, IL? 

These are the requirements: units have been rented in the last 12 months; units are not subsidized units; units are within a 1 mile radius of the subject unit. I am more so trying to find units that are currently being rented, rather than ones that are "for rent" right now. What I have been getting when searching is ones for rent, and I need to find ones being rented currently rather than those that have been sitting empty without renters for months. 

Is there a website that will allow me to input these parameters to get the comparable units I need? Or how do you guys go about finding comparables for your units?