Not later than January 1, 1992, the Secretary shall transmit to Congress a report on the feasibility and advisability of increasing the non-Federal share of costs for new projects in areas where new or substantially improved structures and other constrictions are built or placed in the 100-year flood plain or the 10-year flood plain, as the case may be, after the initial date of the affected governmental unit’s entry into the regular program of the national flood insurance program of the National Flood Insurance Act of 1968 [
42 U.S.C.
4001 et seq.].