You have purchased a new piece of equipment on january 1st, 2010 with an expected life of 5 years. The equipment cost $25,000 and has a salvage value of $5,000. The equipment is capable of producing 40,000 units. Actual production was as follows 20,000 in 2010, 0 units in 2011, 5,000 units in 2012, 10,000 units in 2013 and 5,000 in 2014. calculate depreciation expense for each year of the equipments life using? straight line depreciation, double declining balance depreciation, or units of production depreciation?