Rearden Metals plans to open an open-pit mining operation. The land purchase and costs associated with opening the mining operation will cost $100 million today. The mine is expected to generate $18 million of ore per year for 12 years. At the end of the 12th year, Rearden will have to spend $20 million to restore the land to its original appearance. What is the payback period for Rearden's mining operation? Round your answer to two decimal places.