Highest-earning counties in Delaware Stacker #3. Kent County - Median household income: $72,872- Households earning over $100k: 34.3%- Households earning less than $25k: 13.7% #2. Sussex County - Median household income: $78,162- Households earning over $100k: 37.2%- Households earning less than $25k: 12.8% #1. New Castle County - Median household income: $89,901- Households earning over $100k: 44.7%- Households earning less than $25k: 11.8% Real Window Creative // Shutterstock
