\begin{table}%T4
%\centering
\small
 \caption{Slopes of the age-metallicity relation calculated in the
 Fe4383--H$\beta$ diagram for the three described distributions (see text), and
 for the LDEGs and HDEGs. The last two columns show the dispersion in age and
 metallicity for the different distributions and the subsamples of observed
 galaxies.\label{tab-age-meta}}
\begin{tabular}{@{}l r r r rrr@{}}
 \hline\hline
 Distribution & Age (Gyr)   & [M/H] &\multicolumn{1}{c}{Slope}& 
 \multicolumn{1}{c}{$t$} & 
 \multicolumn{1}{c}{$\sigma_{\rm \log~(age)}$} & 
 \multicolumn{1}{c@{}}{$\sigma_{\rm [M/H]}$}\\[-3.2mm]\\
 \hline
 1            & 8.00       & 0.06      & $-0.668\pm 0.005$ & 2.00& 0.084              &  0.073          \\
 2            & 8.00       & 0.00--0.06& $-0.683\pm 0.005$ & 2.37& 0.084              &  0.076         \\
 3            & 5.62--10.00& 0.00      & $-0.362\pm 0.004$ & 5.41& 0.113              &  0.069       \\
  LDEG         &             &           &$-0.516\pm 0.044$&     & 0.255              & 0.152\\
 \hline
  HDEG         &            &            &$-0.333\pm 0.152 $&     & 0.181              & 0.153\\
 \hline
 \end{tabular}
\end{table}