\begin{table}%t8
\caption{ Intrinsic mean  value  and  variance of  the  logarithm of the X-ray [1.6--10~\kev] and optical flux [$R$~band], at 40~ks  for XRRs/XRFs  with early afterglow observations  and    GRBs. The X-ray flux is in units  of $\rm erg~cm^{-2}~s^{-1}$ and the optical flux
in units  of $\rm W~m^{-2}~Hz^{-1}$.  }
\label{tab12}
%\centering
\small
\begin{tabular}{lcccc}
\hline \hline
Classes & $ \langle \log~(f_{\rm o11.1})\rangle_i $ & $ \langle \sigma \rangle_i$  & $\langle \log~(f_{{\rm x}11.1}) \rangle_i$ & $ \langle \sigma
\rangle_i$  \\
\hline
 %& & & & \\[-8pt]
XRRs/XRFs               &  &   &  $\rm -(12.07^{+0.48}_{-0.52})$ &$\rm 0.85^{+0.46}_{-0.30}$    \\
XRRs/XRFs OT             &   $\rm -(30.38^{+0.48}_{-0.44})$ &   $\rm 0.86^{+0.26}_{-0.14}$ &   &                      \\
XRRs/XRFs without  known redshift        &   &        & $\rm -(12.24^{+0.30}_{-0.27})$&  $\rm 0.51^{+0.22}_{-0.11}$      \\
GRB                        &  &   &$\rm -(12.12^{+0.16}_{-0.14})$   &$\rm 0.45^{+0.14}_{-0.12}$\\
OTGRB                  & $-(30.54\pm0.32)$ &    $\rm 0.53^{+0.21}_{-0.13}$  & &     \\
% & & & & \\[-8pt]
\hline
\end{tabular}
\end{table}