(16) When determining the adjustment of legal regulated rents pursuant to paragraph (2) of this subdivision, where the subject building contains commercial rental space in addition to residential rental space, and the DHCR determines that such commercial space benefits from the improvement, DHCR shall allocate the approved costs between the commercial rental space and the residential rental space based upon the relative square feet of each rental area.
(b) Comparative hardship.
(1) An owner may file an application on forms prescribed by the DHCR, and the DHCR shall grant, on the application of an owner, appropriate rent adjustments as hereinafter provided, where the gross rental income is insufficient to yield to the owner an average annual net income (which shall be computed without regard to debt service, financing costs or management fees), for the three-year period ending on or within six months of the date of the filing of the owner's application, equal to the annual average net income of the property for:
(i) the period 1968-1970; or
(ii) the first three years of operation, if the building was completed after 1968; or
(iii) the first three fiscal years after a transfer of title to a new owner who acquired title to the building as a result of a bona fide sale of the entire building, and who has been unable to obtain requisite records for the fiscal years between 1968 through 1970, despite diligent efforts to obtain the same from predecessors in title, provided that such new owner submits financial data for not less than six years of continuous and uninterrupted operation of the property under his or her ownership.