; or (ii) in the case of individual who has average monthly earnings (as determined under subparagraph (B)) that are in excess of the level of monthly earnings established by the Commissioner to represent substantial gainful activity, the amount of the disability insurance benefit that would otherwise apply for such individual under subsection (a)(2) reduced (but not below zero) by an amount equal to 50 percent of the excess of such individual's average monthly earnings over the level of monthly earnings established by the Commissioner to represent substantial gainful activity. (B) (i) The average monthly earnings for an eligible individual shall be equal to the quotient of— (I) the total amount of wages and self-employment income for such individual in any eligible months during the 2 calendar quarters (as defined in section 213(a)(1)) that precede the most recently completed calendar quarter, and (II) the total number of eligible months during such 2-calendar-quarter period. (ii) For purposes of clause (i), the term eligible month means any month subsequent to the month in which an eligible individual became entitled to a disability insurance benefit. (4) For purposes of paragraph (3)(B), wages and self-employment income of an individual shall be determined based on relevant information for such individual as provided by the State agency responsible for the administration of State unemployment compensation law. (5) For purposes of an eligible individual who has elected to return to employment under this subsection, any services performed or earnings derived from services during the period of such participation shall not be considered for purposes of demonstrating an individual's ability to engage in substantial gainful activity under subsection (d)(4) and shall not be considered substantial gainful activity for purposes of subsection (e). (6) For purposes of this title, the disability insurance benefit received by an individual under this subsection shall not be applied for purposes of determining any monthly