Calculate the percentage of female students.
percentage = CONCAT(DIVIDE(MULTIPLY(COUNT(person.name which is not in male.name)), 100), COUNT(person.name that is IN male.name),'%'); female students refers to person.name who are NOT in male.name;
SELECT CAST(SUM(IIF(T2.name IS NULL, 1, 0)) AS REAL) * 100 / COUNT(T1.name) FROM person AS T1 LEFT JOIN male AS T2 ON T2.name = T1.name