The current spot price of lumber is $$0\mathrm{.}68$ per board foot and the six$-$month lumber futures price is $$0\mathrm{.}69$ per board foot. The proportional storage cost of lumber is $2\mathrm{.}5\%$ per annum with continuous compounding. The interest rate is $4\mathrm{.}5\%$ per annum for all maturities with continuous compounding. What is the current convenience yield? $($Your answer should be in decimals and accurate to three decimal places, i$.$e$.5\mathrm{.}4\%$ should be written as $0\mathrm{.}054).$