To maintain reduced class sizes; purchase textbooks and teaching materials; attract and retain qualified teachers, aides and counselors; enhance core subjects; restore library services and athletic programs; and improve custodial services, shall West Contra Costa Unified School District be authorized to levy, for 5 years only beginning July 1, 2004, an annual tax of 7.2 cents per square foot of total building area or $7.20 per vacant parcel, with an exemption for eligible seniors?