How much percentage of the film did Mary Keitel perform more than Angela Witherspoon?
'Mary Keitel' AND 'Angela Witherspoon' are full name of actors; full name refers to FirstName, LastName; calculation = DIVIDE(SUBTRACT(SUM('Mary Keitel'), SUM('Angela Witherspoon')), SUM('Angela Witherspoon')) * 100
SELECT CAST((SUM(IIF(T1.first_name = 'ANGELA' AND T1.last_name = 'WITHERSPOON', 1, 0)) - SUM(IIF(T1.first_name = 'MARY' AND T1.last_name = 'KEITEL', 1, 0))) AS REAL) * 100 / SUM(IIF(T1.first_name = 'MARY' AND T1.last_name = 'KEITEL', 1, 0)) FROM actor AS T1 INNER JOIN film_actor AS T2 ON T1.actor_id = T2.actor_id