The following balance sheet information is available (amounts in thousands of dollars and duration in years) for a financial institution: T-notes Duration 0.50 Amount $90 T-notes $55 0.90 T-bonds (5 year) $176 X Loans $2724 7.00 Deposits $2092 1.00 Interbank borrowings Equity $238 0.01 $715 Treasury Bonds are five-year maturities paying 6 per cent coupon semi-annually. The sum of its time-weighted PV of cash flows is $773.18. Including the Treasury Bonds, what is the average duration of the bank's total assets?