215.11.15. For the purposes of the payment of benefits, the indexing of the pension or the adjustment of the pension credit, the amount corresponding to the actuarial reduction that has been offset under section 215.11.13 or 215.11.14 shall be added to the pension or, where applicable, to the pension credit and it shall be apportioned among each part of pension or pension credit or, where applicable, in proportion to the amount paid on the amount established pursuant to those sections.