An insurance company expects to make a one-time payout of $10 million dollars in exactly 6 years to fulfil contractual agreements for an investment product. To create portfolio that immunizes this liability, using only a 10-year zero-coupon bond and a 3 year 8% annual coupon bond with a yield to maturity of 10% and a Duration of 2.78 years, one would have to invest ________ of the portfolio value in the zero-coupon bond.