The voters of Los Angeles County approved the assessment by a margin of 73% to 27% on November 5, 2002. The measure was placed on the ballot by the County Board of Supervisors in recognition of the necessity and desirability of providing funding for the Countywide System of Trauma Centers, Emergency Medical Services, and Bioterrorism Response. It was originally estimated that the assessment would yield approximately $168 million annually, representing the first increase in the base property tax approved by the voters since the enactment of Proposition 13 in 1978. The voters approved the annual assessment to commence with County Fiscal Year 2003-04, which was from July 1, 2003 to June 30, 2004, and it appears as a special assessment on the property tax bills. For each fiscal year thereafter, it is subject to the same laws and procedures as the regular property taxes in terms of due dates, installment payments, late payments, penalties, liens, and collections. There are separate procedures for adjustment requests.