For each eligible low-income housing project appraised under section
4103
(a) of this title, the Secretary shall determine whether the aggregate preservation rents for the project determined under paragraph (1) or (2) of section
4104
(b) of this title exceed the amount determined by multiplying 120 percent of the fair market rental (established under section
1437f
(c) of title
42) for the market area in which the housing is located by the number of dwelling units in the project (according to appropriate unit sizes).