You are the owner of a company that specializes in making greasy hamburgers. A local entrepreneur tell you about an exciting business opportunity to recycle your used fry oil to make biodiesel. He says that if you pay him $4,965.86 for equipment, pay $1,625 for his secret process and give up $12,429.19 worth of oil (total over the next 5 years) that you otherwise sell, he will give you back $24,818.22. What return is he actually offering you, stated in % to two decimal places, compounded yearly?