A pension fund has an average duration of its liabilities equal to 10 years. The fund is looking at 6-year maturity zero-coupon bonds and 5% yield perpetuities to immunize its interest rate risk. How much of its portfolio should it allocate to the zero-coupon bonds to immunize if there are no other assets funding the plan? NOTE: Duration for a consol bond is =(1+YTM)/YTM 52.86% 73.3 65.7% 47.14%