which may be based on the following factors: (i) The percentage by which the household income of the eligible policyholder is equal to, or less than, 120 percent of the area median income for the area in which the property to which the policy applies is located. (ii) The number of eligible policyholders participating in the program authorized under this subsection. (iii) The availability of funding. (B) Distribution of premium With respect to the amount of the discounts provided under this subsection in a fiscal year, and any administrative expenses incurred in carrying out this subsection for that fiscal year, the Administrator shall, from amounts made available to carry out this subsection for that fiscal year, deposit in the National Flood Insurance Fund established under section 1310 of the National Flood Insurance Act of 1968 ( 42 U.S.C. 4017 ) an amount equal to those discounts and administrative expenses, except to the extent that section 1310A of the National Flood Insurance Act of 1968 ( 42 U.S.C. 4017a ) applies to any portion of those discounts or administrative expenses, in which case the Administrator shall deposit an amount equal to those amounts to which such section 1310A applies in the National Flood Insurance Reserve Fund established under such section 1310A. (C) Requirement on timing Not later than 21 months after the date of the enactment of this section, the Administrator shall issue interim guidance to implement this subsection which shall expire on the later of— (i) the date that is 60 months after the date of the enactment of this section