The Secretary of the Treasury shall transfer to the Mass Transit Account the mass transit portion of the amounts appropriated to the Highway Trust Fund under subsection (b) which are attributable to taxes under sections
4041 and
4081 imposed after March 31, 1983. For purposes of the preceding sentence, the term “mass transit portion” means, for any fuel with respect to which tax was imposed under section
4041 or
4081 and otherwise deposited into the Highway Trust Fund, the amount determined at the rate of—