A Central Appalachia 12,500 Btu, 1.2 SO₂ coal has an average price of \($60\) per ton. A mine having 7 million tons of coal has a first cost of \($42\) million. The cost of mining is \($45\) per ton. If, during the first 3 years of operation, the mine yields 300,000, 600,000, and 500,000 tons, respectively, determine the depletion allowance using the better method of depletion for each year.