On January 1, 2018, the Excel Delivery Company purchased a delivery van for $51,000. At the end of its five-year service life, it is estimated that the van will be worth $4,200. During the five-year period, the company expects to drive the van 100,000 miles. Required: Calculate annual depreciation for the five-year life of the van using each of the following methods.

4. Units of production using miles driven as a measure of output, and the following actual mileage

year	mileage	depreciation
2018	26000
2019	28000
2020	19000
2021	24000
2022	25000
Total