(1) Commencing January 1, 2006, for all real property for which a final certificate of rehabilitation has been issued, the valuation for purposes of assessment shall be no more than the base-year valuation for eight years following issuance of the final certificate of rehabilitation.

(2) For the four years following the expiration of the eight-year period specified in subsection (1) of this section, the valuation for purposes of the assessment shall be as follows:

(a) For the first year, the base-year valuation plus twenty-five percent of the difference in the base-year valuation and the current year actual value;

(b) For the second year, the base-year valuation plus fifty percent of the difference in the base-year valuation and the current year actual value;

(c) For the third year, the base-year valuation plus seventy-five percent of the difference in the base-year valuation and the current year actual value; and

(d) For the fourth year, the current year actual value.

(3) For purposes of sections 77-1385 to 77-1394, base-year valuation means the assessed valuation of the historically significant real property in the assessment year the preliminary certificate of rehabilitation was issued as certified in subdivision (1)(c) of section 77-1388 or as finally determined if appealed.

(4) If, during the eight-year period and the four-year period specified in subsections (1) and (2) of this section, the State Historic Preservation Officer determines that historically significant real property for which a final certificate of rehabilitation has been issued (a) has been the subject of repair, renovation, remodeling, or improvement but not in accordance with the Standards for Rehabilitation as described in 36 C.F.R. 67.7, as such regulation existed on January 1, 2005, (b) is no longer of historical significance to a qualified historic district, or (c) no longer possesses the qualifications for listing in the National Register of Historic Places, he or she shall revoke the final certificate of rehabilitation by written notice to the owner and transmit a copy of the revocation to the county assessor.

(5) Upon disqualification of any real property receiving base-year valuation under sections 77-1385 to 77-1394, the county assessor shall change the value of such property to its actual value in the assessment year following the revocation of the final certificate of rehabilitation.