\begin{table}
\caption{Example }
\begin{tabular}[l]{@{}lcccccc}\toprule
\hline\noalign{\smallskip}
&  \multicolumn{2}{c} { \textbf{{(M=5)}}}  & \multicolumn{2}{c} { \textbf{ {(M=6)}}}  & \multicolumn{1}{c}{\textbf{Method~of~[6]}}\\
\cline{2-3} \cline{4-5} 
\multicolumn{1}{c}{$s_{i} $}
& \multicolumn{1}{c}{\[\gamma =0.01\]}
& \multicolumn{1}{c}{\[\gamma =0.001\]}
& \multicolumn{1}{c}{\[\gamma =0.01\]}
$& \multicolumn{1}{c}{\[\gamma =0.001\]}
\\ \hline
$0.1$  &$6.6(-5)$  &$2.6(-6)$ &$3.2(-7)$  &$5.6(-7)$  &$5.3(-5)$ \\
$0.2$  &$3.9(-6)$  &$7.1(-6)$ &$2.2(-7)$  &$5.2(-7)$  &$1.3(-4)$ \\
$0.3$  &$7.1(-5)$  &$4.7(-6)$ &$7.1(-7)$  &$8.1(-7)$   &$2.2(-4)$ \\
$0.4$  &$8.2(-5)$  &$7.2(-6)$ &$8.3(-6)$  &$3.1(-7)$   &$3.0(-4)$ \\
$0.5$  & $2.2(-5)$ & $7.0(-6)$ &$6.5(-7)$  &$6.9(-7)$  &$5.9(-4)$ \\
$0.6$  & $4.5(-5)$ & $6.5(-6)$ &$8.7(-6)$  &$4.4(-7)$  &$3.8(-4)$ \\
$0.7$  & $4.0(-5)$ & $3.1(-6)$ &$3.9(-6)$  &$5.8(-6)$  &$5.5(-4)$ \\
$0.8$  & $9.4(-5)$ & $1.1(-6)$ &$6.1(-6)$  &$2.0(-7)$  &$7.2(-4)$ \\
$0.9$  & $3.7(-5)$ & $5.4(-6)$ &$5.7(-6)$  &$5.7(-7)$  &$8.9(-4)$ \\
\noalign{\smallskip}\hline
\end{tabular}
\end{table}