LA = the maximum level of activity

                                     ER_old = the existing VOC emission rate for the affected unit in lb per unit of activity

                                     ER_new = the new VOC emission rate for the affected unit in lb per unit of activity

                                    d = (i) to calculate annual emission reductions, d = 365
                                           (ii) to calculate emission reductions for the remainder of a
                                           control period, d = the number of days remaining in the control period