“Rent constituting property taxes accrued”, except as provided in ss. 71.54 (2) and 71.55 (8), means 25 percent, or 20 percent if heat is included, of the gross rent actually paid in cash or its equivalent by a claimant and his or her household solely for the right of occupancy of their Wisconsin homestead during the calendar year to which the claim relates if that rent constitutes the basis, in the succeeding calendar year, of a claim for relief under this subchapter by such claimant. A marital property agreement or unilateral statement under ch. 766 has no effect in computing rent constituting property taxes accrued for a person whose homestead is not the same as the homestead of that person’s spouse.