; by (ii) the portion of the user fee amount for the current quarter to be assessed on all manufacturers and importers under paragraph (1). (B) No fee in excess of percentage share No manufacturer or importer of electronic nicotine delivery systems shall be required to pay a user fee in excess of the percentage share of the total electronic nicotine delivery system market of the manufacturer or importer. (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