midori sato owns a rental property which had a UCC of $85,000 at the beginning of 2020. after all allowable expenses other than CCA, midori total rental income was $1,000 in 2020 and $10,000 in 2021. midori always deduct the maximum CCA allowed. what is the UCC for the rental property at the end of 2021? ( the property is a class 1 building amortized at 4%)