A coal mine purchased 3 years ago for $7 million was estimated to contain 4,000,000 tons of coal. During the past 3 years, the tonnage of coal removed was 21,000,18,000, and 22,000 tons, respectively. The gross income obtained in these 3 years was $257,000 for the first year, $320,000 for the second year, and $346,000 for the third year. NOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part. Determine the percentage of the purchase price removed from the books through year 3 . The percentage of the purchase price removed from the books through year 3 is %