\begin{table}%t4 \caption {\label{subset}Combined significance of 3 subsets of GRBs selected based on the requirements listed in Sect.~\ref{sect_stacking}.} % using soft cuts %\centering \par \begin{tabular}{lcrr} \hline\hline % & \multicolumn{2}{c}{soft-cut} & \multicolumn{2}{c}{standard-cut} \\ % & excess & significance ($\sigma$) & excess & significance ($\sigma$) \\ %\hline %Sample A & $-$132 & $-$2.48 & $-$47 & $-$1.80 \\ %Sample B & 12 & 0.35 & 30 & 1.76 \\ %Sample C & $-$12 & $-$0.22 & 17 & 0.57 \\ %all GRBs & $-$138 & $-$1.78 & $-$5 & $-$0.13 \\ & Number & Soft-cut & Standard-cut \\ & of GRBs & analysis & analysis \\ \hline Sample A & 10 & --2.13 & --1.81 \\ Sample B & 6 & --0.20 & 1.45 \\ Sample C & 11 & --0.53 & 0.48 \\ All GRBs & 21 & --1.98 & --0.18 \\ \hline \end{tabular} \end{table}