Jim and Mary Cummings just had their first child, and they want to begin saving for college expenses. They estimate they will need a college fund worth $100,000 to pay for four years of college costs. They plan to set aside $2,700 at the end of each year for the next 18 years, at an investment interest rate of 8% interest. Given that plan, how long will it take Jim and Mary to accumulate the money they need?