\begin{table}%t1 \caption{\label{number}Number of each subsample.} %\centering \small \begin{tabular}{r|rrrr|c} \hline \hline {Method} & \multicolumn{4}{c|}{Emission-line diagram} &{Infrared luminosity bin} \\ {class} & star-forming & composite & LINER & Seyfert 2 & \\ \hline total number &419 & 326 & 69 & 35 & 849\\ \hline ULIG \& LIG & 100 & 158 & 26 & 15 & 299 \\ starburst & 250 & 152 & 32 & 17 & 451 \\ normal & 69 & 16 & 11 & 3 & 99 \\ \hline \end{tabular} \end{table}