This download includes three different data sets that were provided to ProPublica Illinois and the Chicago Tribune by the Cook County Assessor's Office. The three datasets are:
- The raw first-pass or initial assessment values and market values for each property, identified only by its Property Index Number (PIN), which is unique for each parcel of property. Covers 2002-2015
- Property assessment data on each PIN that was the subject of an appeal, including property information, as well as initial assessed values, second-pass assessed values, and the final assessed values (incorporating any successful appeals to the Cook County Board of Review), as well as attorney names. Covers 2003-2016.
- The raw final assessed values that were submitted to the Cook County Board of Review by the Cook County Assessor's office for each PIN. Covers 2002-2015.
The Assessor's Office did not provide documentation.
Provided in collaboration with Chicago Tribune