\begin{table}%t1
\par
\caption {\label{table_stat}Quality statistics ($C_1$, $C_2$, $P_1$, $P_2$, $S_{\rm gal}$, and
$f_{\rm I}$, see text for details) of the reconstructed group catalogue,
for two different redshift bins and the whole redshift range. }     
%\centering
\par
\begin{tabular}{c c c c}        
 \multicolumn{4}{c}{}\\  
 \multicolumn{4}{c}{Quality statistics for $N \geq 2$}\\  
\hline\hline 
Quality parameter & $0.2\leq z \leq 0.6$ & $0.6\leq z \leq 1.0$ &  $0.2\leq z \leq 1.0$\\    
\hline                        
   $C_1$          & $0.68 \pm 0.03$      & $0.57 \pm 0.04$      &  $0.63 \pm 0.03$     \\
   $C_2$          & $0.56 \pm 0.04$      & $0.49 \pm 0.05$      &  $0.53 \pm 0.03$     \\
   $P_1$          & $0.56 \pm 0.02$      & $0.55 \pm 0.04$      &  $0.56 \pm 0.02$     \\
   $P_2$          & $0.48 \pm 0.04$      & $0.50 \pm 0.04$      &  $0.49 \pm 0.03$      \\
   $S_{\rm gal}$      & $0.72 \pm 0.03$      & $0.59 \pm 0.03$      &  $0.67 \pm 0.02$        \\
   $f_{\rm I}$        & $0.38 \pm 0.02$      & $0.43 \pm 0.04$      &  $0.40 \pm 0.02$        \\
\hline                                   
\end{tabular}
\par
\vspace{0.5cm}
\par
\begin{tabular}{c c c c}        
%\hline\hline                 
 \multicolumn{4}{c}{Quality statistics for $N\geq 3$}\\  
 \hline\hline 
Quality parameter & $0.2\leq z \leq 0.6$ & $0.6\leq z \leq 1.0$ &  $0.2\leq z \leq 1.0$\\    
\hline                        
   $C_1$          & $0.73 \pm 0.06$      & $0.57 \pm 0.05$      &  $0.67 \pm 0.04$     \\
   $C_2$          & $0.65 \pm 0.06$      & $0.52 \pm 0.06$      &  $0.60 \pm 0.03$     \\
   $P_1$          & $0.61 \pm 0.03$      & $0.58 \pm 0.05$      &  $0.60 \pm 0.03$     \\
   $P_2$          & $0.50 \pm 0.05$      & $0.51 \pm 0.07$      &  $0.50 \pm 0.05$      \\
   $S_{\rm gal}$      & $0.75 \pm 0.04$      & $0.60 \pm 0.04$      &  $0.70 \pm 0.03$        \\
   $f_{\rm I}$        & $0.35 \pm 0.03$      & $0.40 \pm 0.05$      &  $0.37 \pm 0.02$        \\
\hline                                   
\end{tabular}
\tablefoot {The
first table shows $C_1$, $C_2$, $P_1$, $P_2$, $S_{\rm gal}$, and $f_{\rm I}$
for all groups, while the second table shows these parameters 
for groups with at least 3~members. Each parameter is computed as the mean over the 
20~VVDS-like
mocks, and the associated error is its rms.}
\end{table}