Johnson Corporation bought a machine on January 1, 2021 for $10,000. The machine had a salvage value of $2,000, a useful life of 4 years and Johnson uses the straight-line method of depreciation. After one year, Johnson changes the total useful life of the machine to 6 years rather than 4 years and changes the salvage value to $1,000 instead of $2,000. Johnson will revise its depreciation, what is the depreciation expense for 2022?