Section 29.45.210 - Hearing(a) If an appellant fails to appear, the board of equalization may proceed with the hearing in the absence of the appellant.(b) The appellant bears the burden of proof. The only grounds for adjustment of assessment are proof of unequal, excessive, improper, or under valuation based on facts that are stated in a valid written appeal or proven at the appeal hearing. If a valuation is found to be too low, the board of equalization may raise the assessment.(c) The board of equalization shall certify its actions to the assessor within seven days. Except as to supplementary assessments, the assessor shall enter the changes and certify the final assessment roll by June 1.(d) An appellant or the assessor may appeal a determination of the board of equalization to the superior court as provided by rules of court applicable to appeals from the decisions of administrative agencies. Appeals are heard on the record established at the hearing before the board of equalization.