Calculate the percentage of business which opened on Sunday from 9AM to 9PM based on the number of business opened on Sunday.
Sunday refers to day_of_week = 'Sunday' where day_id = 1; opened from 9AM to 9PM refers to Business_Hours where opening_time = '9AM' and closing_time = '9PM'; DIVIDE(COUNT(opening_time = '9AM' and closing_time = '9PM' and day_of_week = 'Sunday'), COUNT(opening_time = NOT NULL and closing_time = NOT NULL and day_of_week = 'Sunday')) as percentage;
SELECT CAST(SUM(CASE WHEN T2.opening_time = '9AM' AND T2.closing_time = '9PM' THEN 1 ELSE 0 END) AS REAL) * 100 / COUNT(T1.day_id) FROM Days AS T1 INNER JOIN Business_Hours AS T2 ON T1.day_id = T2.day_id WHERE T1.day_of_week = 'Sunday'