On 1 January 2022, Company A purchased equipment for $60,000, with a useful life of 10 years and a residual value of $4,000. Company A uses the straight-line depreciation method to calculate depreciation expense. On 31 December 2024, Company A decided to revise the estimated useful life of the equipment to 8 years, with no change in residual value. Calculate the depreciation expense for the years 2022, 2023, and 2024 and the adjustment to depreciation expense that Company A needs to make in 2024.