Kernrechtsfrage
Whether the cantonal court arbitrarily disregarded the landlord's operating-cost evidence in the yield calculation.
Extrahierter Entscheid
No. The documents were not sufficient to prove the operating costs, so excluding them from the yield calculation was not arbitrary.
Extrahierte Begründung
The submitted statements were internal and largely unsupported by vouchers; several items could not be checked, and some costs varied sharply from year to year. The landlord bore the burden of proving the facts supporting the refusal of a rent reduction.