\begin{table}%t3
\caption{\label{magfactor}Measurements of the magnification factors.}  
\small%\centerline
{
 \begin{tabular}{ll}
\hline \hline
\multicolumn{1}{c}{Epoch} & \multicolumn{1}{c}{NE/SW~ratio} \\
\hline
1995 Sep. 29 $^\dagger$ & 1.6 $\pm$ 0.2 \\
1995 Sep. 30 $^\dagger$ & 1.6 $\pm$ 0.2 \\
1995 Oct. 01 $^\dagger$ & 1.5 $\pm$ 0.1 \\
1995 Oct. 26 $^\dagger$ & 1.8 $\pm$ 0.2 \\
1999 Jun. 11 & 1.65 $\pm$ 0.02 \\
2001 Mar. 20 & 1.55 $\pm$ 0.04 \\
2001 Jun. 29 & 1.65 $\pm$ 0.02 \\
2002 Jun. 25 & 1.68 $\pm$ 0.05 \\
2003 Fev. 26 $^\ddagger$ & 1.66 $\pm$ 0.07 \\
2003 Mar. 01 $^\ddagger$ & 1.75 $\pm$ 0.07 \\
\hline
\end{tabular}}
\smallskip
$^\dagger$ Re-reduction of previous PdBI observations (\cite{wc98}).\\
$^\ddagger$ Baselines longer than 300 m were flagged out.
\end{table}