White to Non-White Racial Dissimilarity (5-year estimate) Index for New Castle County, DE was 37.62% in January of 2022, according to the United States Federal Reserve. Historically, White to Non-White Racial Dissimilarity (5-year estimate) Index for New Castle County, DE reached a record high of 41.03 in January of 2010 and a record low of 36.87 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 New Castle County, DE - last updated from the United States Federal Reserve on May of 2024.