White to Non-White Racial Dissimilarity (5-year estimate) Index for Middlesex County, CT was 39.54% in January of 2021, according to the United States Federal Reserve. Historically, White to Non-White Racial Dissimilarity (5-year estimate) Index for Middlesex County, CT reached a record high of 42.97 in January of 2019 and a record low of 38.54 in January of 2017. Trading Economics provides the current actual value, an historical data chart and related indicators for White to Non-White Racial Dissimilarity (5-year estimate) Index for Middlesex County, CT - last updated from the United States Federal Reserve on May of 2024.