Consider the following set of messages with their frequencies:
$$\begin{array}{|c|c|c|} \hline \textbf{Message} & \textbf{Frequency} \\ \hline A & 50\: \text{million} \\ \hline B & 10\: \text{million} \\ \hline C& 24\: \text{million} \\ \hline D & 36\: \text{million} \\ \hline \end{array}$$
The percentage improvement for total binary stream transmission using Huffman Encoding over simple encoding is _______ %.