testing period
(iii)For purposes of this subsection, the term “testing period” means the 3-year period ending with the close of the taxable year of the corporation preceding the payment (or such part of such period as may be applicable). If the corporation has no gross income for such 3-year period (or part thereof), the testing period shall be the taxable year in which the payment is made. (iv)In the case of a taxable year for which the testing period includes 1 or more taxable years beginning before— (I)a corporation meets the 80-percent foreign business requirements of this subparagraph if and only if the weighted average of— (II)the active foreign business percentage for such taxable year shall equal the weighted average percentage determined under subclause (I).