California Code, Elections Code - ELEC § 13117

(a) Commencing with the November 3, 1998, general election, all state measures in all elections at which state measures are submitted to a vote of the voters shall be numbered in a continuous sequence, commencing with the number “1” and continuing in numerical sequence for a period of 10 years from the year of commencement.

(b) At the completion of a 10-year cycle, the numbering sequence shall recommence with the number “1” at the next election at which state measures are submitted to a vote of the voters.