\begin{table}%T4
 \caption{Summary of the power-law model fits to the
  INTEGRAL-IBIS-ISGRI total-spectra of \rxs1708 summing observations
  taken in intervals of $\sim$1~year and for the total exposure.}
\small%\centerline
$$
\begin{tabular}{l r@{ $\pm$ }l r@{ $\pm$ }l l }
\hline
\hline\noalign{\smallskip}
Rev.&
\multicolumn{2}{c}{$\Gamma$}& 
\multicolumn{2}{c}{$F_{20-150} \times 10^{-11}$} & 
\chir (d.o.f.) \\
 &  \multicolumn{2}{c}{}  & \multicolumn{2}{c}{[\ecs]}&\\
\hline
037--120 & 1.18&0.14 & 5.47&0.43 & 1.64 (14) \\
164--246 & 1.40&0.15 & 5.97&0.55 & 1.09 (14) \\
283--366 & 0.97&0.12 & 7.13&0.44 & 0.52 (14) \\
399--485 & 1.00&0.21 & 8.72&0.61 & 1.67 (14) \\
%\hline
037--485 & 1.13&0.06 &  6.61&0.23$^\dagger$ & 1.13 (14)\\
\multicolumn{6}{l}{$^\dagger F_{20-175} = (7.76 \pm 0.34) \times 10^{-11}$~\ecs}\\
\hline
\end{tabular}$$
\smallskip
 For each spectrum are given the revolution interval over
which \rxs1708 observations are summed, the photon index, the 20$-$150~keV flux and \chir.
\label{tab:rxsfits}
\end{table}