DOE may increase the qualifying volume of the biodiesel component of fuel for purposes of allocation of credits under this subpart only after it:

(a) Collects data establishing that the average annual alternative fuel use in light duty vehicles by fleets and covered persons exceeds 450 gallons or gallon equivalents; and

(b) Conducts a rulemaking to amend the provisions of this subpart to change the qualifying volume to the average annual alternative fuel use.