The total amount of bonds issued, including bonds issued pursuant to Chapter 1 (commencing with Section 15100), shall not exceed 1.25 percent of the taxable property of the district as shown by the last equalized assessment of the county or counties in which the district is located. The bonds may only be issued if the tax rate levied to meet the requirements of Section 18 of Article XVI of the California Constitution in the case of indebtedness incurred by a school district pursuant to this chapter, at a single election, would not exceed thirty dollars ($30) per year per one hundred thousand dollars ($100,000) of taxable property when assessed valuation is projected by the district to increase in accordance with Article XIII A of the California Constitution. 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.