gas importer The term fluorinated greenhouse gas importer means any importer who is included under— (A) the industrial gas supplier source category under subpart OO of part 98 of title 40, Code of Regulations, as in effect on the date of the enactment of the American Opportunity Carbon Fee Act of 2019 , or (B) the source category under subpart QQ of such part (as so in effect). (4) Applicable percentage The term applicable percentage means the percentage determined in accordance with the following table: In the case of any taxable year beginning in calendar year: The applicable percentage is: 2020, 2021, or 2022 10 percent 2023 20 percent 2024 30 percent 2025 40 percent 2026 50 percent 2027 60 percent 2028 70 percent 2029 80 percent 2030 90 percent 2031 or thereafter 100 percent. (d) Exemption for exports For purposes of determining fluorinated greenhouse gases produced or imported under subsection (a), there shall not be taken into account any fluorinated greenhouse gases exported from the United States in bulk or exported from the United States in equipment pre-charged with fluorinated greenhouse gases or containing fluorinated greenhouse gases in closed cell foams. (e) Refund for consumptive uses and destruction In the case of a person who uses any fluorinated greenhouse gas for which a fee has been imposed under paragraph (1) or (2) of subsection (a) as an input for a manufactured good that transforms the fluorinated greenhouse gas such that it cannot later be emitted or otherwise destroys the gas (without emissions), a refund shall be allowed to such person in the same manner as if it were an overpayment of the fee imposed by such subsection in an amount that is equal to the product of— (1) an amount equal to the applicable percentage (as defined in subsection (c)(4)) of the applicable amount under section 4691(b), for the calendar year in which such fluorinated greenhouse gas was used or destroyed, and (2) the excess (if any) of— (A) the total carbon dioxide equivalent of the fluorinated greenhouse gases