I have a table as shown below which is missing a horizontal line across a \multicolumn as shown below 
The code I used is
\begin{figure}[!h]
\flushleft
\begin{minipage}[c]{0.6\textwidth}
\centering
\includegraphics[width=1\linewidth,valign=c]{images/chap4/comparingThoughputQos0}
\end{minipage}
\centering
\begin{minipage}[c]{0.38\textwidth}
\centering
\renewcommand{\arraystretch}{1.0}
\begin{tabular}{| c | c | c |}
\hline
\multirow{2}{*}{$\lambda_{{RE}}$} & $NS_{{1}}$ & $NS_{{2}}$ \\
\cline{2-3}
& \multicolumn{2}{c}{$\mu_{RE-SCEPA}$} \\
\hline
50 & 00 & 00 \\
200 & 00 & 00 \\
500 & 00 & 00 \\
1000 & 00 & 00 \\
2000 & 00 & 00 \\
3000 & 00 & 00 \\
\hline
\end{tabular}
\end{minipage}
\caption{Impact of number of sensors on $\mu_{RE}$ for different $\lambda_{{RE}}$}\label{fig:comparingThoughput}
\end{figure}
What am I doing wrong?
