I don’t know.
Nor does the Chicago Police Department. They don’t keep track of individual bike thefts, which are categorized with all other larcenies. Even if they wanted to give you a number, they wouldn’t have one to give.
Talking to individuals who’ve had their bikes stolen, I found one sentiment shared time and time again: “The police won’t do anything.””—Chicago Police Less Willing To Curb Bike Thefts Than Some Other Cities, Internet Vigilantes « CBS Chicago (via themason)