An investor trading in bonds is looking for 15 % return on his purchases. He buys bonds with a few years left before maturity, holds them, and redeems them for face value when they mature. Looking through the bond listings, he finds a bond listed with a $7,000 face value, that pays 8 % interest on its face value each year, and is priced at $4,801 . How many years (at most) must be left before maturity on this bond in order to meet the investor’s desired percent return? (Enter your answer as a number rounded to one decimal place, without the percent sign.)