The $4$-hr unit hydrograph for a catchment is given in the table below. What would be the maximum ordinate of the S – curve (in $m^3/s$) derived from this hydrograph?
$$\begin{array}{|c|c|c|c|c|c|c|c|c|c|c|c|} \hline \\ \text{Time (hr)} & 0 & 2 & 4 & 6 & 8 & 10 & 12 & 14 & 16 & 18 & 20 & 22 & 24 \\ \hline \text{Unit hydrograph} \\ \text{ ordinate} (m^3/s) & 0 & 0.6 & 3.1 & 10 & 13 & 9 & 5 & 2 & 0.7 & 0.3 & 0.2 & 0.1 & 0 \\ \hline \end{array}$$