A condenser is used as a heat exchanger in a large steam power plant in which steam is condensed to liquid water. The condenser is a shell and tube heat exchanger which consists of $1$ shell and $20,000$ tubes. Water flows through each of the tubes at a rate of $1 \mathrm{~kg} / \mathrm{s}$ with an inlet temperature of $30^{\circ} \mathrm{C}$. The steam in the condenser shell condenses at the rate of $430 \mathrm{~kg} / \mathrm{s}$ at a temperature of $50^{\circ} \mathrm{C}$. If the heat of vaporization is $2.326 \mathrm{MJ} / \mathrm{kg}$ and specific heat of water is $4 \mathrm{~kJ} /(\mathrm{kg} . \mathrm{K})$, the effectiveness of the heat exchanger is ___________ (rounded off to $3$ decimal places).