such year, over (II) the aggregate rental reduction credit amounts allocated for such year. (iii) Formula for allocation of unused credit among qualified States The amount allocated under this subparagraph to a qualified State for any calendar year shall be the amount determined by the Secretary to bear the same ratio to the aggregate unused rental reduction credits of all States for the preceding calendar year as such State's population for the calendar year bears to the population of all qualified States for the calendar year. For purposes of the preceding sentence, population shall be determined in accordance with section 146(j). (iv) Qualified State For purposes of this subparagraph, the term qualified State means, with respect to a calendar year, any State— (I) which allocated its entire State rental reduction credit ceiling for the preceding calendar year, and (II) for which a request is made (at such time and in such manner as the Secretary may prescribe) to receive an allocation under clause (iii). (5) Other definitions For purposes of this section— (A) Rental reduction credit agency The term rental reduction credit agency means any agency authorized by a State to carry out this section. Such authorization shall include the jurisdictions within the State where the agency may allocate rental reduction credit amounts. (B) Possessions treated as States The term State includes a possession of the United States. (C) Family The term family has the same meaning as when used in the United States Housing Act of 1937. (d) Modifications To correct inaccurate amounts due to incorrect estimates (1) Establishment of reserves (A) In general Each rental reduction credit agency of a State shall establish a reserve for the transfer and reallocation of amounts pursuant to this paragraph, and notwithstanding any other provision of this section, the rental reduction credit amount allocated to any building by such agency shall be zero unless such agency has in effect such a reserve at the time of the allocation of such credit