72.1. Where a three-year roll is not deposited pursuant to section 70 or 71 and the preceding roll applies for an additional fiscal year pursuant to section 72, the assessor is bound to deposit a new roll within a period beginning on 15 August and ending on 15 September of that fiscal year for the two ensuing fiscal years. The new roll shall be regarded as a three-year roll and the second fiscal year for which it applies shall be regarded as the third fiscal year of the three-year roll. If the preceding roll is a three-year roll, the additional fiscal year for which it applies shall be regarded as the third fiscal year of that roll.