CREATE TABLE table_204_572 (id DECIMAL, "rank" DECIMAL, "county" TEXT, "per capita\ income" TEXT, "median\ household\ income" TEXT, "median\ family\ income" TEXT, "population" DECIMAL, "number of\ households" DECIMAL)

what is the difference between the per capita income in richland county and in sheridan county ?
SELECT ABS((SELECT "per capita\nincome" FROM table_204_572 WHERE "county" = 'richland') - (SELECT "per capita\nincome" FROM table_204_572 WHERE "county" = 'sheridan'))
SELECT ABS((SELECT "per capita\nincome" FROM "table_204_572" WHERE "county" = 'richland') - (SELECT "per capita\nincome" FROM "table_204_572" WHERE "county" = 'sheridan'))