Fluss AB has 8.5 per cent coupon bonds making annual payments with a YTM of 7.2 per cent. The current yield on these bonds is 7.6 per cent. The par value of the bond is 1,000.

How many years do these bonds have left until they mature? (Do not round intermediate steps. Round your answer to the nearest whole amount of years (so do not use decimals in your answer).)