Database: restaurant
Question: What is the percentage of restaurants in the Bay Area region that scored over 4 for the review rating?
SQL: SELECT CAST(SUM(IIF(T2.review > 4, 1, 0)) AS REAL) * 100 / COUNT(T2.id_restaurant) FROM geographic AS T1 RIGHT JOIN generalinfo AS T2 ON T1.city = T2.city WHERE T1.region = 'bay area'