(a) In addition to the general tax computed under Subchapter C, an employer entitled to an experience rate shall pay a replenishment tax at the rate computed by:
(1) dividing the numerator described by Subsection (b) by the denominator described by Subsection (c);
(2) multiplying that result by 100 to obtain a percentage; and
(3) rounding that result to the nearest hundredth.
(b) The numerator is an amount equal to one-half of the amount of benefits paid by all employers during the 12 months ending the preceding September 30 that are not effectively charged.

(c) The denominator is an amount equal to the taxable wages paid by all employers during the four quarters ending the preceding June 30.