I created the following table in LaTeX but it was too wide to fit on the page, even in landscape format. How can I solve this problem? The code is:
\begin{sidewaystable}
\caption{My caption}
\label{my-label}
\centering
\begin{tabular}{|l*{16}{|c}|}
\hline
\multicolumn{1}{|m{1.5cm}|}{\textbf{ }} & \multicolumn{5}{|m{5cm}|}{\textbf{Benchmark}} & \multicolumn{5}{|m{5cm}|}{\textbf{Graduate}} & \multicolumn{5}{|m{5cm}|}{\textbf{Our Approach}} \\ \hline \hline
\multicolumn{1}{|m{1.5cm}|}{\textbf{metric}} & \textbf{Acc.} & \textbf{P.(FR)}& \textbf{P.(NFR)} & \textbf{R.(FR)} & \textbf {R.(FR) } & \textbf{Acc.} & \textbf{P. (FR)} & \textbf{P. (NFR)} & \textbf{R.(FR)} & \textbf{R. (FR) } & \textbf{Acc.} & \textbf{P. (FR)} & \textbf{P. (NFR)} & \textbf{R.(FR)} & \textbf{R. (FR) } \ \hline
\multicolumn{1}{|m{1.5cm}|}{\textbf{Case#1}} & 100% & 100% & 100% & 100% & 100% & 93% & 90% & 93.8% & 94% & 90% & 95% & 91% & 100% & 100% & 90% \ \hline
\multicolumn{1}{|m{1.5cm}|}{\textbf{Case#2}} & 100% & 100% & 100% & 100% & 100% & 86% & 82% & 90% & 92% & 80% & 85% & 100% & 76% & 70% & 100% \ \hline
\multicolumn{1}{|m{1.5cm}|}{\textbf{Case#3}} & 100% & 100% & 100% & 100% & 100% & 91% & 93% & 88.6% & 88% & 94% & 90% & 88% & 81% & 80% & 90% \ \hline
\multicolumn{1}{|p{1.5cm}|}{\textbf{Average}} & 100% & 100% & 100% & 100% & 100% & 90% & 88.3% & 90.8% & 91.3% & 88% & 90% & 93% & 85.66% & 83.33% & 93.33% \ \hline
\end{tabular}
\end{sidewaystable}

