At 25^oC molar conductance of 0.1 molar aqueous solution of ammonium hydroxide is 9.54 ohm^$-$1 cm² mol^$-$1 and at infinite dilution its molar conductance is 238 ohm^$-$1 cm² mol^$-$1. The degree of ionisation of ammonium hydroxide at the same concentration and temperature is