A coal mine purchased three years ago for $3,425,000 was estimated to contain 6,500,000 tons of coal. During the past three years, the amount of coal removed was 18,000, 27,000, and 35,000 tons, respectively. The gross income obtained in these three years was $257.000 for the first year. $320,000 for the second year, and $340,000 for the third year. Determine the percentage of the purchase price depleted thus far. Assume coal removed = sold. (Enter the answer in %6, 0.05 -5%, enter the value of 5)