Bonita Towing Company purchased a tow truck for $175000 on January 1, 2020. It was originally depreciated on a straight-line basis over 10 years with an assumed salvage value of $36000. On December 31, 2022, before adjusting entries had been made, the company decided to change the remaining estimated life to 4 years (including 2022) and the salvage value to $6000. What was the depreciation expense for 2022?