\begin{table}%t1
\caption{Contingency tables for bin 50 of the PSR B1133+16 data,
showing the frequency of occurrence of all possible combinations in the
single pulses. The top table corresponds to the 4.85 GHz and the bottom
table to the 1.41 GHz data.}\label{tab1}
%\centering
\par
\begin{tabular}{c|ccc}
\hline  \hline
4.85 GHz & Mode 1 & Mode 2 & Undefined \\ \hline
$V +$ & 390 & 452 & 1366 \\
$V -$ & 659 & 436 & 1475 \\
\end{tabular}
\\
\begin{tabular}{c|ccc}
\hline  \hline
1.41 GHz & Mode 1 & Mode 2 & Undefined \\ \hline
$V +$ & 269 & 632 & 1506 \\
$V -$ & 442 & 386 & 1563 \\
\hline
\end{tabular}
\end{table}