\begin{table}%T13
%\centering
\par
\caption{Emission line region minimum sizes at the different epochs studied
(in cm). The first line display the narrow component region values (N),
while the second line displays the broad component region ones (B).
\label{Tab_Radius}}
\par
\begin{tabular}{cccc}
\hline \hline 
year&
1995&
1999&
2001\\
\hline
\par
$\log{R'}$ (N)&
$13.1\pm0.5$&
$12.9\pm0.3$&
$12.5\pm0.4$\\
%\hline 
$\log{R'}$ (B)&
$12.8\pm0.8$&
$13.0\pm0.4$&
$12.6\pm0.5$\\
\hline
\end{tabular}
\end{table}