White to Non-White Racial Dissimilarity (5-year estimate) Index for Contra Costa County, CA was 42.23% in January of 2022, according to the United States Federal Reserve. Historically, White to Non-White Racial Dissimilarity (5-year estimate) Index for Contra Costa County, CA reached a record high of 43.81 in January of 2012 and a record low of 42.23 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 Contra Costa County, CA - last updated from the United States Federal Reserve on May of 2024.