Question: Corporate Property Investors built which shopping center in the Middlesex County, Massachusetts area?
Sentence (from "Middlesex County, New Jersey"): As of the 2016 Census estimate, the county's population was 837,073, making it the state's second-most populous county, an increase of 3.4% from the 2010 United States Census, when its population was enumerated at 809,858, making it the second-most populous county in the state.
Relevant evidence: No