Ideally, UWSC would be able to report on the % of households that receive SSI, cash public assistance income, or food stamps/SNAP. At the present time, data inclusive of SSI is not readily usable. What we do know from the American Community Survey table "Receipt of Supplemental Security Income (SSI), Cash Public Assistance Income, or Food Stamps/SNAP in the Past 12 Months by Household Type for Children Under 18 Years in Households": 17.9% of households with children receive these benefits (2018 data: 2,878 households/16,097 total households with children).
FY20-21 note: This data is not yet available for 2020. The Census Bureau notes: "The Census Bureau will not release its standard 2020 ACS 1-year estimates because of the impacts of the COVID-19 pandemic on data collection. Experimental estimates, developed from 2020 ACS 1-year data, will be available on the ACS Experimental Data webpage no later than November 30th."