A 15-year bond, which was issued on June 1, 2015, has a current price of $800, a maturity value of $1,000, and matures in 5 years. If interest is paid semi-annually and the bond is currently priced to yield 8%, what is the bond's duration? (Assume a basis of 360-day year, 30-day months). Round your answer to the nearest hundredth.