How many films rented to the customer RUTH MARTINEZ were returned in August, 2005?
returned in August, 2005 refers to year(return_date) = 2005 and month (return_date) = 8
SELECT COUNT(T1.customer_id) FROM customer AS T1 INNER JOIN rental AS T2 ON T1.customer_id = T2.customer_id WHERE T1.first_name = 'RUTH' AND T1.last_name = 'MARTINEZ' AND STRFTIME('%m',T2.return_date) = '8' AND STRFTIME('%Y', T2.return_date) = '2005'