California Code, Government Code - GOV § 21311

(a) “Monthly allowance” means any allowance payable monthly to a retired person, a survivor or beneficiary of a member or a retired person, other than a monthly installment of a basic death benefit, the commuted value of an unpaid temporary annuity, or an optional settlement 1, or allowances payable under Article 3 (commencing with Section 21570) of Chapter 14. There shall be excluded from the monthly allowance, for purposes of any adjustment under this article, any portion of the allowance derived from accumulated additional contributions of a member.

(b) “Base allowance” means the amount of monthly allowance that would be payable to the recipient at the time of an annual adjustment under this article had this article not been enacted.

(c) Effective January 1, 1978, “Consumer Price Index” means the United States city average “Consumer Price Index for All Urban Consumers.” The “Consumer Price Index” for any period prior to January 1, 1978, means the United States city average consumer price index. Should the reference base of the consumer price indices (presently 1957-59=100) be changed, each of the indices used to determine the consumer price index as defined in this section will be the indices converted to the new base by standard statistical methods.

(d) “Base year” means: