\begin{table}%t4
\caption{Mean reddening of sub-samples with different strengths of the \ion{Si}{ii}~1526~line
detected at the redshift of the DLA~system.}\label{tab4}
%\centering
\small
\begin{tabular}{cccccc}
\hline \hline
%&&&&& \\[-8pt]
 &   &      $W_{\ion{Si}{ii}} $& $<$$1$ \AA\  &  $ W_{\ion{Si}{ii}} $& $\geq$$1$ \AA\ \\
 \hline
Color & Sample & $n$ &  $\langle E \rangle$ & $n$ &  $\langle E \rangle$ \\
      &        &     &   [10$^{-3}$ mag]    &     &  [10$^{-3}$ mag] \\
\hline
$(r-z) $ & 1& $151$ & $26 \pm 12$ & $29$ & $ 41 \pm 25$ \\
              & 2 & $150$ & $21 \pm 11$ & $29$ & $ 41 \pm 25$ \\
                & 3 & $149$ & $17 \pm 10$ & $29$ & $ 41 \pm 25$ \\
\hline               
$(g-z)$ & 1 & $142$ & $51 \pm 14$  & $29$ & $114 \pm 40$ \\
              & 2 & $141$ & $46 \pm 13$  & $29$ & $114 \pm 40$\\      
                & 3 & $140$ & $42 \pm 13$  & $29$ & $114 \pm 40$\\               
\hline 
\end{tabular}
\end{table}