A 20-year callable, convertible bond has a face value of $1,000 and pays a 6% coupon annually. The conversion price is $75. The stock currently sells for $25 per share. The stock price is expected to grow at 8% per year. The bond is expected to be called when the conversion value is $1,150. The required return on this bond is 8%. In how many years will this bond be converted?