\begin{table}%t4
  %\centering
\par
  \caption {\label{tab:HRfits}Summary of the fits of the hardness-ratio selected subsamples.}
\par
  \begin{tabular}{lccc}
    \hline
    \hline
    Band (keV) &   $N_{\rm sou}$ & $\theta_0$   & $\gamma-1$     \\
               &             &  (arcsec)     \\
    \hline
    Soft (0.5--2) $HR\geq-0.2$  &   4038 & $\rm 27.1_{-17.7}^{+14.5}$ & $\rm 1.17_{-0.35}^{+0.26}$   \\
       &    & 8.3$\pm$0.5 & 0.8 $\rm (fixed)$    \\
    \noalign{\smallskip}
    Soft (0.5--2) $HR<-0.2$  &    27791 & $\rm 24.8_{-2.7}^{+2.6}$ & $1.17\pm0.05$   \\
       &    & 7.5$\pm$0.1 & 0.8 $\rm (fixed)$    \\
    \noalign{\smallskip}
    Hard (2--10) $HR\geq-0.2$ &   3425  & $\rm 33.1_{-17.8}^{+13.3}$ & $\rm 1.37_{-0.36}^{+0.28}$    \\
      &    & $6.8\pm0.5$ & 0.8 $\rm (fixed)$    \\
    \noalign{\smallskip}
    Hard (2--10) $HR<-0.2$ &  6006  & $\rm 27.0_{-9.9}^{+8.5}$ & $\rm 1.27_{-0.20}^{+0.17}$    \\
      &    & $6.2\pm0.3$ & 0.8 $\rm (fixed)$    \\
    \hline
  \end{tabular}
\end{table}