; and (iv) establish objective criteria for periodic review and updates to the formula to reflect changes in available science and data. (C) Minimum allocation threshold The Secretary shall, by regulation, establish a minimum allocation threshold. (D) Interim allocation Until such time that the Secretary issues final regulations under this paragraph, the Secretary shall— (i) allocate assistance from the Fund using the formula allocation methodology published in accordance with paragraph (4); and (ii) include an additional amount for mitigation equal to 15 percent of the total estimate of unmet need. (6) Allocation of funds (A) In general The Secretary shall— (i) except as provided in clause (ii), not later than 90 days after the President declares a major disaster, use best available data to determine whether the major disaster is catastrophic and qualifies for assistance under the formula described in paragraph (4) or (5), unless data is insufficient to make this determination