The local roll as delivered to the auditor pursuant to Section 617, including any changes made by the county board during the month of July, together with the board roll as transmitted to the auditor pursuant to Section 756 and the estimate with any changes transmitted pursuant to Section 755, shall become the last equalized roll on August 20, and such rolls together shall continue to be the last equalized roll, except as otherwise provided in this chapter, (a)for the purpose of computing any debt limit for the issuance of bonds of any public entity that is based on a percentage of assessed valuation as shown on the last equalized assessment roll and (b)for all other purposes, until the assessment roll for the following year becomes the last equalized roll in accordance with the provisions of this section.