How many of the worst actors are men and how many of the worst actors are women? Indicate your answer in ratio form.
The worst actors means a_quality = 0; Men and male share the same meaning; men actors refers to a_gender = 'M'
SELECT CAST(SUM(IIF(a_gender = 'M', 1, 0)) AS REAL) / SUM(IIF(a_gender = 'F', 1, 0)) FROM actors WHERE a_quality = 0
database name:db_id movielens
users table users Cols: user id dtype integer, age dtype text, user gender dtype text, occupation dtype text, 
directors table directors Cols: director id dtype integer, director quality dtype integer, average revenue dtype integer, 
actors table actors Cols: actor id dtype integer, actor gender dtype text, actor quality dtype integer, 
movies table movies Cols: movie id dtype integer, year dtype integer, is English dtype text, country dtype text, runningtime dtype integer, 
movies2actors table movies2actors Cols: movie id dtype integer, actor id dtype integer, cast number dtype integer, 
movies2directors table movies2directors Cols: movie id dtype integer, director id dtype integer, genre dtype text, 
u2base table u2base Cols: user id dtype integer, movie id dtype integer, rating dtype text, 
