Balance Sheet Duration $,$calculate duration

$\backslash$table$[[,$Book Value,Coupon,$\backslash$table$[[$Repricing$],[$Period in$],[$years$]],\backslash$table$[[$Yield to$],[$Maturity$]],\backslash$table$[[$Market$],[$Value$]]],[$Assets:$,80,-,-,,],[$Cash$,1,000,6\mathrm{.}00\%,2\mathrm{.}00,7\mathrm{.}00\%,982],[\backslash$table$[[3$ year GTBs $($Held for$],[$Trading$)]],500,7\mathrm{.}00\%,2\mathrm{.}00,8\mathrm{.}00\%,491],[\backslash$table$[[5,$ year GTBs$],[($Available for sale$)]],2,000,8\mathrm{.}00\%,9\mathrm{.}00,9\mathrm{.}00\%,1,878],[\backslash$table$[[10$ year GTBs $($held to$],[$maturity$)]],100,-,-,-,100],[\backslash$table$[[$Investment in shares$],[($Held for Trading$)]],6,000,10\mathrm{.}00\%,3\mathrm{.}00,10\mathrm{.}00\%,6,000],[\backslash$table$[[3$ year Commercial$],[$Loan$]],320,-,-,-,320],[$Non Earning Assets,$10,000,-,-,8\mathrm{.}90\%,9,851$