\begin{table}%T13
\par
        \caption{ Time lags and CCF coefficients for the whole monitoring
 period, for the three periods based on the profile shapes, and for the division based on the three 
values of the
 continuum intensity. }\label{tab13}
 \small%\centering
\par
\begin{tabular}{ccccccc}
\hline
\hline
Period &H$\alpha$&  CCF&H$\alpha$-cent& H$\beta$&  CCF&H$\beta$-cent\\
 \hline\noalign{\smallskip}
  1996--2006 & $\rm 5.70^{+27.05}_{-5.70}$ & $\rm 0.87^{+0.02}_{-0.02}$&80.36 $\pm$ 12.93& 
$\rm 5.09^{+27.89}_{-5.09}$& $\rm 0.93^{+0.01}_{-0.01}$& 69.79 $\pm$ 11.91\\
\noalign{\smallskip}
  First& $\rm 0.68^{+3.30}_{-0.68}$ & $\rm 0.67^{+0.09}_{-0.10}$& 0.62 $\pm$ 1.11&
$\rm 1.11^{+4.90}_{-1.11}$ & $\rm 0.82^{+0.04}_{-0.05}$&11.61 $\pm$ 2.87 \\
Second& $\rm 21.86^{+9.03}_{-10.53}$ &$\rm 0.78^{+0.11}_{-0.14}$& 66.07 $\pm$ 9.95&
$\rm 11.15^{+5.00}_{-4.17}$ &$\rm 0.88^{+0.06}_{-0.07}$&8.15 $\pm$ 2.38     \\
Third& $\rm 0.81^{+1.55}_{-0.81}$ &$\rm 0.94^{+0.02}_{-0.02}$&3.18 $\pm$ 1.76&
$\rm 0.81^{+2.19}_{-0.81}$& $\rm 0.86^{+0.03}_{-0.04}$& 16.17 $\pm$ 3.14\\
\noalign{\smallskip}\hline
Continuum &H$\alpha$&  CCF&H$\alpha$-cent& H$\beta$&  CCF&H$\beta$-cent\\
\hline\noalign{\smallskip}
$F_{\rm con}^1$ & $\rm 0.27^{+0.73}_{-0.27}$ & $\rm 0.51^{+0.22}_{-0.27}$&--&
$\rm 25.15^{+13.77}_{-20.16}$ &$\rm 0.50^{+0.23}_{-0.28}$&--\\
$F_{\rm con}^2$& $\rm 19.36^{+10.42}_{-5.44}$ & $\rm 0.66^{+0.14}_{-0.17}$&0.56 $\pm$ 6.245& 
$\rm 0.62^{+3.49}_{-0.62}$ &$\rm 0.70^{+0.07}_{-0.08}$&2.71 $\pm$ 5.22\\
$F_{\rm con}^3$& $\rm 1.19^{+6.01}_{-1.19}$ & $\rm 0.67^{+0.07}_{-0.08}$&13.65 $\pm$ 4.47&
$\rm 0.70^{+2.94}_{-0.70}$ &$\rm 0.82^{+0.04}_{-0.04}$&12.28 $\pm$ 5.26\\
\hline
\end{tabular}
\end{table}