Per Illinois Motor Vehicle Theft Protection & Insurance Verification Council-
"A rise of vehicle theft rates in Illinois means the risk to insure a vehicle is higher, thus we all pay through higher insurance rates. Since the Council's inception in 1991, with various Council initiatives working across the state, vehicle theft is down 77 percent. The reduction in vehicle theft helps stabilize insurance premiums.
When vehicle theft rates rise in Illinois, so do insurance premiums.
The reduction in vehicle theft equals savings in your pocket."
source: http://www.cyberdriveillinois.com/MVTPIV/home.html