An investor trading in bonds is looking for 4% 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 exist2,000 face value, that pays 3% interest on its face value each year, and priced at exist1, 747. 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.)