Gov. Code, § 31739.2

Every retirement allowance for time commencing on the effective date of this section to or on account of any member of this system or of a superseded system, who was retired for disability on or after January 1, 1948, but prior to February 1, 1955, or such other date prior to February 1, 1955, as the board of supervisors in any county shall specify by resolution, is hereby increased by twenty-five dollars ($25) per month if the retired member is entitled to be credited with 20 years or more of service, or, if the retired member is entitled to be credited with less than 20 years of service, by an amount which bears the same ratio to twenty-five dollars ($25) as the member’s completed years of service with which the member is entitled to be credited bears to 20 years.

This section shall not be operative in any county until such time as the board of supervisors shall, by resolution adopted by majority vote, make the provisions of this section applicable in such county.