; (bb) the percentage growth in the number of shipments within each category of exempted water heater relative to the baseline data described in subclause (I); and (cc) the determination of the Secretary as to whether the number of shipments for any category of exempted water heater have increased by more than 25 percent compared to the baseline data for that category. (C) Inclusion of exempted water heaters (i) In general The Secretary shall, by regulation, revise the definition of water heater under section 321(27) to include an exempted water heater under subparagraph (A) of that section if the Secretary makes an affirmative determination under subparagraph (B)(iii)(II)(cc) for that category of exempted water heater. (ii) Energy conservation standards Any category of exempted water heater included in the definition of water heater under clause (i) shall be required to meet the energy conservation standards applicable to an electric or gas storage type water heater under this part. (iii) Effective date For any category of exempted water heater, the Secretary shall carry out clause (i), and require compliance under clause (ii), not later than 1 year after the date on which the Secretary makes the affirmative determination described in clause (i) for that category. (8) Standards for multi-input electric storage water heaters A multi-input electric storage water heater shall be subject to the test procedures, energy conservation standards, labeling (if applicable), and certification requirements— (A) for electric storage water heaters under this part