\begin{table}%t1
\caption{\label{t1}Luminosity-samples studied with their respective luminosity interval in absolute Petrosian r-magnitude, and the redshift samples that can be compared.}
%\centering
\par
\small\begin{tabular}{cccc}
\hline
\hline
L-sample&Redshift&${M}_r$&Redshift-samples\\\
&completeness&& compared\\\hline
$a$&$z_1$&($-$23.8, $-$21.7)&$z_1$, $z_0$\\\
$b$&$z_2$&($-$24.8, $-$22.9)&$z_2$, $z_1$\\\
$c$&$z_3$&($-$24.8, $-$23.1)&$z_3$, $z_2$, $z_1$\\\hline
\end{tabular}
\end{table}