; United States city average) between 2021 and the applicable year. (2) Determination of user fee by company The total user fee to be paid by each manufacturer or importer of electronic nicotine delivery systems shall be determined for each quarter pursuant to a formula developed by the Secretary. (3) Timing of assessment The Secretary shall notify each manufacturer and importer of electronic nicotine delivery systems subject to this section of the amount of the quarterly assessment imposed on such manufacturer or importer under this subsection for each quarter of each fiscal year. Such notifications shall occur not later than 30 days prior to the end of the quarter for which such assessment is made, and payments of all assessments shall be made by the last day of the quarter involved. (4) Calculation of market share Beginning not later than fiscal year 2020, and for each subsequent fiscal year, the Secretary shall ensure that the Food and Drug Administration is able to determine— (A) the annual amount of total sales in the electronic nicotine delivery system market of the United States; and (B) the applicable percentage shares under paragraph (2). (c) Crediting and availability of fees (1) In general Fees authorized under subsection (a) shall be collected and available for obligation only to the extent and in the amount provided in advance in appropriations Acts. Such fees are authorized to remain available until expended. Such sums as may be necessary may be transferred from the Food and Drug Administration—Salaries and Expenses account without fiscal year limitation to such appropriation account for salaries and expenses with such fiscal year limitation. (2) Availability Fees appropriated under paragraph (3) shall be— (A) transferred to the Centers for Disease Control and Prevention