Consider a bond with 30 years to maturity that pays an annual coupon rate of 6.6%. The bond has a face value of $1,000 and is currently priced at $1,000. You purchase this bond today. Immediately after you purchase it, market rates change to 8% and remain there for the next 10 years at which time you sell the bond. With respect to the bond above, what is the duration of this bond?