California Code, Education Code - EDC § 17423

No district shall enter into any lease or agreement pursuant to this article if at the time 50 percent of any remaining rental payments for use of the building or site and building which would become due from the district pursuant to this article, including the lease or agreement to be entered into, if the leases and agreements were to run their full term, plus the total amount of district bonded indebtedness outstanding at the time, shall exceed 7.5 percent for elementary school districts and high school districts and 12.5 percent for unified school districts 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. For the purpose of this section, the taxable property of the district shall be determined upon the basis that the district's assessed value has not been reduced by the exemption of the assessed value of business inventories in the district or reduced by the homeowners' property tax exemption.