For movie titled 'Welcome to the Dollhouse', how many percentage of the ratings were rated with highest score.
rated with highest score refers to rating_score = 5; percentage = MULTIPLY(DIVIDE(SUM(rating_score = 5), COUNT(rating_score)), 100)
SELECT CAST(SUM(CASE WHEN T2.rating_score = 5 THEN 1 ELSE 0 END) AS REAL) * 100 / COUNT(*) FROM movies AS T1 INNER JOIN ratings AS T2 ON T1.movie_id = T2.movie_id WHERE T1.movie_title = 'Welcome to the Dollhouse'