\begin{table}%T4
%\centering
\small
\caption{Fractional distribution of the total $H$-index, $\eta$, for different magnetic flux thresholds.}\label{t4}
\begin{tabular}{c c c}\hline \hline\\[-3.2mm] 
$\Phi_0$~(Mx~cm$^{-2}$) & \# & $\eta$ (\%) \\ \hline 
4.   & 38~905  & 63.7  \\%\hline 
10.  & 26~071  & 44.5  \\%\hline 
50.  & 11~190  & 20.4  \\%\hline 
100. & 4933   & 9.2 \\%\hline 
150. & 1709   & 3.3 \\ %\hline 
200. & 329      & 0.6  \\\hline 
\end{tabular} 
\end{table}