Check out this fascinating interactive graphic, in The Wall Street Journal, on the growth in high-rate (subprime) loans. In Illinois, high-rate loans were 161% of the market in 2004 and 30.9% in 2006.
In the Chicago metro area high-rate loans accounted for 16.3% of all loans in 2004 and 32.9% of all loans in 2006. Dozens and dozens of metro areas had higher percentages than Chicago, led (!) by Miami at 48.2%.
High-rate loan volume in the Chicago metro area in 2006 was $23.8 billion against 139,585 loans, for an average loan of $170,548. This would seem to indicate that these loans were more prevalent on lower-priced properties.