the state legislature and signed by the governor. Mandatory referendum Under California law, certain types of bills passed by the State Legislature and signed by the Governor must be submitted to the voters as a referendum at the next statewide election. Legislative bills that require mandatory referendums include state constitutional amendments, bond measures, and amendments to previously approved voter initiatives. More than 50 percent of the voters must then support these amendments or new laws on the ballot for them to go into effect. Optional referendum Laws already adopted by the state legislature may be vetoed by means of a referendum. This is also known as a "petition referendum" or "people's veto". The process is similar to an initiative as noted above, except that it is an already passed law submitted as a petition to the Attorney General. The proponent, however, only has 90 days after the law in question is enacted to submit the request to the Attorney General for a circulating title and summary, gather the signatures, and file the petitions with the county elections officials; otherwise, it must go through the initiative process, submitted as a proposed amendment. Laws that are ineligible for optional referendums include urgency statutes, statutes calling elections, and statutes providing for tax levies or appropriations for usual, current state expenses. To qualify on the ballot, a referendum petition must be signed by at least five percent of the number of voters in the previous gubernatorial election. The signature checking process by the counties is basically the same as the initiative process. The counties take a random sample of 3 percent or 500 of the signatures, whichever is greater. If the statewide random sample total projects more than 110 percent of the required number of signatures, the referendum automatically qualifies; if less than 95 percent, it fails; and if it is between 95 and 110 percent, a full check of all the signatures is performed. Unlike initiatives which must qualify 131 days before the election to appear on the ballot, a referendum can qualify up to 31 days before. If the referendum receives more "no" votes than "yes" votes, the law is repealed. As of 2020, only 94 optional referendums proposed since 1912 had received a circulating title and summary, and of those only 52 qualified for the ballot. Proposition numbering Originally, ballot propositions were given a number starting at one each election. This