By what percentage is the average salary of Trainees higher than the minimum salary of this postion?
AVG(salary); Trainee is a position title; minimum salary refers to minsalary; calculation = DIVIDE(SUBTRACT(AVG(salary), minsalary), minsalary) * 100
SELECT 100 * (AVG(CAST(REPLACE(SUBSTR(T1.salary, 4), ',', '') AS REAL)) - CAST(REPLACE(SUBSTR(T2.minsalary, 4), ',', '') AS REAL)) / CAST(REPLACE(SUBSTR(T2.minsalary, 4), ',', '') AS REAL) AS per FROM employee AS T1  INNER JOIN position AS T2  ON T1.positionID = T2.positionID WHERE T2.positiontitle = 'Trainee'