\begin{table}%t7
\caption{The mean flux density, the standard deviation and the modulation indices for the flux density variability of B~2005+430 at different frequencies between 1990 and~2004.}\label{tab:m_index}
%\centering
\par
\begin{tabular}{cccc}
\hline\hline 
${\rm Frequency (GHz)}$ & $\langle S\rangle {\rm ~(Jy)}$ &  $\sigma$  & ${m (\%)}$ \\ 
\hline 
5 & $2.86 \pm 0.02$ & 0.217 & 7.61 \\
8 & $3.03 \pm 0.02$ & 0.369 & 12.15 \\
15 & $2.63 \pm 0.02$ & 0.374 & 14.24 \\
22 & $1.95 \pm 0.03$ & 0.500 & 25.67 \\
37 & $1.84 \pm 0.03$ & 0.363 & 19.81 \\
\hline
\end{tabular}
\end{table}