The total amount of bonds issued pursuant to this chapter and Chapter 1.5 (commencing with Section 15264) shall not exceed 1.25 percent of the taxable property of the school district or community college district, or the school facilities improvement district, if applicable, as shown by the last equalized assessment of the county or counties in which the district is located. For purposes of this section, the taxable property of a district for any fiscal year shall be calculated to include, but not be limited to, the assessed value of all unitary and operating nonunitary property of the district, which shall be derived by dividing the gross assessed value of the unitary and operating nonunitary property within the district for the 1987–88 fiscal year by the gross assessed value of all unitary and operating nonunitary property within the county in which the district is located for the 1987–88 fiscal year, and multiplying that result by the gross assessed value of all unitary and operating nonunitary property of the county on the last equalized assessment roll.