Among the films that the customer RUTH MARTINEZ has rented, how many of them are released in 2006?
release in 2006 refers to release_year = 2006
SELECT COUNT(T1.customer_id) FROM customer AS T1 INNER JOIN rental AS T2 ON T1.customer_id = T2.customer_id INNER JOIN inventory AS T3 ON T2.inventory_id = T3.inventory_id INNER JOIN film AS T4 ON T3.film_id = T4.film_id WHERE T4.release_year = 2006 AND T1.first_name = 'RUTH' AND T1.last_name = 'MARTINEZ'