\begin{table}%t4
   \caption{\label{pol}Polarization properties of the supernova remnants. The polarized
   intensity was corrected for noise bias (see text Sect.~3.2). The peak polarization
   in Col.~4 is an approximate value. SNRs with no detectable polarization
   were removed from the table.}
\small      %\centering
$$
\begin{tabular}{lr@{$~\pm~$}lr@{$~\pm~$}lc}
  \hline\hline
   Source & 
   \multicolumn{2}{c}{PI$_{1420}$ [mJy]} &
   \multicolumn{2}{c}{\%--Pol.} &
   Peak \%--Pol. \\
   \hline
   G65.7$+$1.2&441&14&11.0&0.7&26 \\
   G67.7$+$1.8&49&2&7.2&0.5&50 \\
   G69.0$+$2.7&4230&130&7.6&0.7&48 \\
   G73.9$+$0.9&99&4&1.3&0.1&9  \\
   G74.9$+$1.2&117&4&1.6&0.3&5 \\
   G76.9$+$1.0&8&1&0.6&0.1&3 \\
   G78.2$+$2.1&970&50&0.4&0.1&2 \\
   G82.2$+$5.3&210&10&0.23&0.02&14 \\
   G84.2$-$0.8&14&1&0.19&0.03&13 \\
   G89.0$+$4.7&6690&750&3.7&0.4&34 \\
   G93.7$-$0.2&5240&180&15.0&1.8&43 \\
   G106.3$+$2.7&444&16&9.3&1.0&41 \\
   G107.5$-$1.5 & 32 & 4 & 46 & 7 & 71 \\
   G109.1$-$1.0&210&12&1.2&0.1&8 \\
   G113.0$+$0.2&125&7&\multicolumn{2}{c}{--}& 50 \\
   G114.3$+$0.3&108&4&2.0&0.3&31 \\
   G116.5$+$1.1&210&30&2.0&0.3&50 \\
   G116.9$+$0.2&30&3&0.4&0.1&35 \\
   G120.1$+$1.4&1010&30&2.5&0.1&6 \\
   G126.2$+$1.6&52&7&0.8&0.2&80 \\
   G127.1$+$0.5&640&70&6.6&0.8&49 \\
   G130.7$+$3.1&1620&100&5.1&0.4&10 \\
   G160.9$+$2.6&4900&170&9.1&0.6&59 \\
   G166.0$+$4.3&440&50&8.6&1.2&57 \\
   \hline
\end{tabular}
$$
\end{table}