You are a bond portfolio manager at XYZ inc. and you administer a $50 million portfolio. The portfolio currently has a duration of 9.5 years. You expect interest rates to rise in the future and want to hedge your portfolio against interest-rate risk. T-bond futures have a duration of 3 years and are currently trading at a price of 108 (that is, $108,000 per futures contract). How many futures contracts do you need to fully hedge your portfolio against the interest-rate risk?