Windsor, Inc. purchased a delivery truck for $32,000 on January 1, 2022. The truck has an expected salvage value of $4,000, and is expected to be driven 100,000 miles over its estimated useful life of 8 years. Actual miles driven were 16,600 in 2022 and 13,100 in 2023. (a1) Calculate depreciable cost per mile under units-of-activity method. (Round answer to 2 decimal places, e.g. 0.50.) Depreciable cost per mile