The limiting molar conductivities of \( \mathrm{NaI} \), \( \mathrm{NaNO_3} \) and \( \mathrm{AgNO_3} \) are \( 12.7 \), \( 12.0 \) and \( 13.3 \) \( \text{mS m}^2 \text{mol}^{-1} \), respectively (all at \( 25^\circ \text{C} \)). The limiting molar conductivity of \( \mathrm{AgI} \) at this temperature is ________ \( \text{mS m}^2 \text{mol}^{-1} \).