CREATE TABLE table_name_81 (legs VARCHAR(255), venue VARCHAR(255), runner_up__average_in_final_ VARCHAR(255))
What is the legs when the venue is rwe-sporthalle, mülheim and the runner-up (average in final) is simon whitlock (99.59)?
    
SQL: SELECT legs FROM table_name_81 WHERE venue = "rwe-sporthalle, mülheim" AND runner_up__average_in_final_ = "simon whitlock (99.59)"