Equipment costing $$140,000$ is expected to have a residual value of $$12,500$ at the end of its six$-$year useful life. The equipment is metered so that the number of units processed is counted. The equipment is designed to process $1,020,000$ units in its lifetime. In Year $1$ and Year $2$ the equipment processed $220,000$ units and $180,000$ units respectively. Calculate the depreciation expense for Year $1$ and Year $2$ using each of the following methods: