Nathan Webb, a die-hard Michigan Fan, opened a credit card 20 years ago, the last time Michigan won in Columbus (subtle reminder that Michigan is bad), when he was 2 years old. Now that he is graduating from Ohio State, he has decided to pay it off. His first and only purchase on this card was $5,627 on that card was made 20 years ago. Now, his credit statement has a says he owes $30,270. What is the annual interest rate on his credit card?