CREATE TABLE table_39685 ("County" TEXT, "Per capita income" TEXT, "Median household income" TEXT, "Median family income" TEXT, "Population" FLOAT, "Number of households" FLOAT)

How many households are in highlands county?
SELECT AVG("Number of households") FROM table_39685 WHERE "County" = 'highlands'
SELECT AVG("Number of households") FROM "table_39685" WHERE "County" = 'highlands'