White to Non-White Racial Dissimilarity (5-year estimate) Index for Middlesex County, NJ was 36.95% in January of 2022, according to the United States Federal Reserve. Historically, White to Non-White Racial Dissimilarity (5-year estimate) Index for Middlesex County, NJ reached a record high of 39.47 in January of 2013 and a record low of 36.95 in January of 2022. 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, NJ - last updated from the United States Federal Reserve on June of 2024.