Christian Yip purchased a condominium in 1997. His down payment was $20; 000 which is 40% of the listed price. He nanced the remaining amount as 30-year mortgage at 7%, compounded monthly. His monthly payments at the time of purchase was calculated as $200. It is now 2017 (20 years later) and Christian sold the condominium for $100; 000, immediately after making his 240th payment on the unit. What is his effective annual internal rate of return on this investment?