-- Database schema
| geographic : city [ TEXT ] primary_key , county [ TEXT ] , region [ TEXT ] | generalinfo : id_restaurant [ INTEGER ] primary_key , label [ TEXT ] , food_type [ TEXT ] , city [ TEXT ] generalinfo.city = geographic.city , review [ REAL ] | location : id_restaurant [ INTEGER ] primary_key location.id_restaurant = generalinfo.id_restaurant , street_num [ INTEGER ] , street_name [ TEXT ] , city [ TEXT ] location.city = geographic.city |
-- -- What is the percentage of restaurants in the Bay Area region that scored over 4 for the review rating?

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';