Who are the top 5 actors with the highest number of films? List their full names and calculate the average number of films for each of the actors.
actors with highest number of films refers to actor_id with Max(Count(film_id)); full name refers to first_name, last_name; average number of film = Divide (Count(film_id), 5)
SELECT T.first_name, T.last_name, num FROM ( SELECT T1.first_name, T1.last_name, COUNT(T2.film_id) AS num FROM actor AS T1 INNER JOIN film_actor AS T2 ON T1.actor_id = T2.actor_id INNER JOIN film AS T3 ON T2.film_id = T3.film_id GROUP BY T1.first_name, T1.last_name ) AS T ORDER BY T.num DESC LIMIT 5