In California, Proposition 13 was passed in 1978. It limits the property tax rate to 1% of assessed value, plus any additional ad valorem (based on value) tax rate necessary to fund local voter-approved general obligation bonds and other indebtedness. Therefore, any tax rate you see on your tax bill in addition to the 1% represents a debt or debts approved by the voters.
Prior to Proposition 13, tax rates set to cover an entity’s general obligation bonds and other indebtedness could be passed by a majority vote. Proposition 13 changed this by requiring a two-thirds vote. In the November 2000 election, voters approved Proposition 39 allowing the voting threshold for school general obligation bonds to be lowered to 55%, if the school board so chooses.