What is the percentage of restaurants that serve American food in Dublin city?
American food refers to food_type = 'american food'; percentage = divide(count(id_restaurant), count(id_restaurant where food_type = 'american food')) where city = 'dublin' * 100%
SELECT CAST(SUM(IIF(food_type = 'american food', 1, 0)) AS REAL) * 100 / COUNT(id_restaurant) FROM generalinfo WHERE city = 'dublin'
database name:db_id restaurant
geographic table geographic Cols: city dtype text, country dtype text, region dtype text, 
generalinfo table generalinfo Cols: id restaurant dtype integer, label dtype text, food type dtype text, city dtype text, review dtype real, 
location table location Cols: id restaurant dtype integer, street number dtype integer, street name dtype text, city dtype text, 
