CREATE TABLE table_203_61 (id DECIMAL, "rank" DECIMAL, "nation" TEXT, "gold" DECIMAL, "silver" DECIMAL, "bronze" DECIMAL, "total" DECIMAL)

what is the difference of silver medals between south africa and kenya ?
SELECT (SELECT "silver" FROM table_203_61 WHERE "nation" = 'south africa') - (SELECT "silver" FROM table_203_61 WHERE "nation" = 'kenya')
SELECT (SELECT "silver" FROM "table_203_61" WHERE "nation" = 'south africa') - (SELECT "silver" FROM "table_203_61" WHERE "nation" = 'kenya')