(2.1.4) The minimum standards for the annual firearms proficiency course of fire for __________shall be a minimum of 30 rounds of duty ammunition fired at a range of at least 50 yards, including at least one timed reload; however, an agency may, in its discretion, allow a range of less than 50 yards but not less than 10 yards if the minimum passing percentage is raised to 90. (Rule 217.21)