\begin{table}%T2
\caption{\label{table:2}Summary of data sets presented here.}             
\small      
%\centering
\par
\begin{tabular}{c c c c c c c c }     % 8 columns 
\hline\hline \noalign{\smallskip}      
&&Criterion 1 &\multicolumn{2}{c}{Criterion 2}  &\multicolumn{2}{c}{Criterion 3} & Criterion 4\\
Data set& Two beam& Residual&Planet to& Planet  &Active durations& Active duration&Time between\\
&  null depth&starlight& star contrast&SNR  & Star-and-planet &Planet only&data sets\\
&&suppression&&&Star only\\
\par
\hline  \noalign{\smallskip}                     
6--18 & 8.5 $\times$ 10$^{-6}$ &293 & 3.8 $\times$ 10$^{-7}$ &14.0  &10~262 s&2100 s\\
&&&&&10~258 s\\
7--10 &7.4 $\times$ 10$^{-6}$ &250 &4.4 $\times$ 10$^{-7}$ & 16.4  &10~076 s& 2086 s &20 days\\
&&&&&10~064 s\\
7--23 &5.5 $\times$ 10$^{-6}$ &326 &4.4 $\times$ 10$^{-7}$ & 26.9  &10~562 s&2026 s  &12 days \\
&&&&&10~566 s\\
\hline                  
\end{tabular}
\end{table}