Any such member shall have the right to reduce his or her normal contributions under the system on account of his or her compensation in any position, at his or her option to be exercised by an election in writing on a form furnished by the system, such election to be effective on the first day of the pay period next following the date of which it is filed in the office of the system. Such reduction of normal contributions shall apply only to time during which such member is covered under the Social Security provisions, on and after the effective date of such election, and the amount of such reduction, which may be changed from time to time by such member in accordance with rules and regulations of the retirement system manager, shall not be more in any month than the amount of contributions deducted from his or her compensation for such month on account of his or her coverage under such provisions. (Prior code § 34.10.1002)