Database: movies_4
Question: Find the difference in percentage of the movies under keywords of "woman director" and "independent film".
SQL: SELECT CAST((SUM(CASE WHEN T1.keyword_name = 'woman director' THEN 1 ELSE 0 END) - SUM(CASE WHEN T1.keyword_name = 'independent film' THEN 1 ELSE 0 END)) AS REAL) * 100 / SUM(CASE WHEN T1.keyword_name = 'independent film' THEN 1 ELSE 0 END) FROM keyword AS T1 INNER JOIN movie_keywords AS T2 ON T1.keyword_id = T2.keyword_id