\begin{table}%T4
\par
\caption{\label{tab4}The errors in measurements (e$\pm \sigma$)
for  all line segments (see Table~\ref{tab3}) of H$\alpha$ and
H$\beta$ given in percent. For each segment, the mean-year flux is
also given in units $10^{-13} \ \rm erg \ cm^{-2} s^{-1} $.}
\small%\centering
\par
\begin{tabular}{ccccccccccccc}
\hline\hline
 Year & \multicolumn{2}{c}{Ha(--5)}  &  \multicolumn{2}{c}{Ha(+5)}  & \multicolumn{2}{c}{Ha(--4)}   & \multicolumn{2}{c}{Ha(+4)} &
\multicolumn{2}{c}{Ha(--3)} & \multicolumn{2}{c}{Ha(+3)}\\
   & Flux & ($e\pm \sigma$) & Flux  &($e\pm \sigma$)& Flux & ($e\pm \sigma$)& Flux & ($e\pm \sigma$)& Flux & ($e\pm \sigma$) & Flux & ($e\pm \sigma$)\\
 \hline
 1996  & 6.327  &  9.6$~\pm~$ 9.7  & 7.052  & 13.3$~\pm~$10.5  & 12.456  &  9.9$~\pm~$5.9  & 12.494   & 11.7$~\pm~$7.1  & 22.736 &  9.1$~\pm~$6.8  & 17.722  & 10.9$~\pm~$7.1\\
 1997  & 3.904  & 11.1$~\pm~$ 6.1  & 4.950  &  9.7$~\pm~$ 0.8  &  8.100  &  6.7$~\pm~$8.8  &  10.048  & 9.7$~\pm~$3.8   & 18.741 &  6.7$~\pm~$9.2  & 16.634  & 9.1$~\pm~$5.3\\
 1998  & 2.497  & 11.7$~\pm~$ 4.2  & 4.516  &  7.2$~\pm~$ 6.6  &  6.381  &  5.4$~\pm~$2.4  &  8.904   & 7.4$~\pm~$4.8   & 16.570 &  3.2$~\pm~$2.9  & 16.518  & 4.6$~\pm~$4.7\\
 1999  & 2.030  & 14.3$~\pm~$18.3  & 5.133  &  6.2$~\pm~$ 3.8  &  5.649  &  2.1$~\pm~$3.0  &  8.776   & 3.3$~\pm~$1.1   & 16.851 &  2.2$~\pm~$2.0  & 16.470  & 2.1$~\pm~$1.0\\
 2000  & 1.647  &  5.3$~\pm~$ 4.3  & 3.460  &  4.3$~\pm~$ 3.5  &  3.561  &  4.4$~\pm~$4.4  &  5.570   & 4.2$~\pm~$3.5   &  9.204 &  4.2$~\pm~$3.8  &  7.770  & 3.8$~\pm~$3.6\\
 2001  & 2.251  &  5.5$~\pm~$ 5.3  & 2.906  &  7.3$~\pm~$ 6.2  &  3.671  &  4.7$~\pm~$6.0  &  5.220   & 5.9$~\pm~$6.1   &  7.249 &  7.3$~\pm~$6.0  &  7.760  & 8.1$~\pm~$7.0\\
 2002  & 3.686  &  3.5$~\pm~$ 0.4  & 3.016  &  3.0$~\pm~$ 1.3  &  5.041  &  2.7$~\pm~$2.4  &  6.443   & 4.9$~\pm~$5.3   &  7.792 &  3.6$~\pm~$1.4  & 10.742  & 4.1$~\pm~$5.1\\
 2003  & 3.004  &  5.7$~\pm~$ 5.0  & 4.186  &  2.9$~\pm~$ 1.7  &  4.447  &  4.9$~\pm~$2.4  &  7.560   & 3.4$~\pm~$1.3   &  9.104 &  4.0$~\pm~$2.3  & 14.034  & 2.9$~\pm~$2.1\\
 2004  & 3.261  &  3.2$~\pm~$ 0.8  & 2.722  &  3.3$~\pm~$ 1.8  &  4.340  &  6.1$~\pm~$2.3  &  5.299   & 1.9$~\pm~$1.3   &  6.619 &  5.7$~\pm~$2.4  &  9.922  & 3.9$~\pm~$2.1\\
 2005  & 2.908  &  4.3$~\pm~$ 1.3  & 2.350  &  7.1$~\pm~$ 6.7  &  4.122  &  4.4$~\pm~$3.4  &  4.687   & 5.9$~\pm~$6.2   &  5.756 &  4.5$~\pm~$3.1  &  8.575  & 5.5$~\pm~$4.3\\
 2006  & 2.906  &  1.7$~\pm~$ 0.4  & 1.938  &  1.7$~\pm~$ 1.7  &  3.979  &  3.0$~\pm~$2.7  &  4.115   & 3.0$~\pm~$1.9   &  5.784 &  2.7$~\pm~$2.8  & 10.459  & 1.9$~\pm~$1.3\\
\hline
mean  && 6.9$~\pm~$4.1 & &  6.0$~\pm~$3.4 & & 4.9$~\pm~$2.2 & &5.6$~\pm~$3.0 & &4.8$~\pm~$2.1 & &5.2$~\pm~$3.0\\
\hline
&&&&&&\\
 \hline
Year & \multicolumn{2}{c}{Hb(--5)}  &  \multicolumn{2}{c}{Hb(+5)}  & \multicolumn{2}{c}{Hb(--4)}   & \multicolumn{2}{c}{Hb(+4)} &
\multicolumn{2}{c}{Hb(--3)} & \multicolumn{2}{c}{Hb(+3)}\\
& Flux & ($e\pm \sigma$) & Flux  &($e\pm \sigma$)& Flux & ($e\pm \sigma$)& Flux & ($e\pm \sigma$)& Flux & ($e\pm \sigma$) & Flux & ($e\pm \sigma$)\\
\hline
 1996  & 2.511 &   3.2$~\pm~$0.17  & 2.535 &    6.5$~\pm~$ 5.3  & 4.965 &  7.0$~\pm~$ 5    & 4.470 &  7.1$~\pm~$1.5  & 8.003 &  7.6$~\pm~$6.1 & 5.838 &  6.6$~\pm~$2.5\\
 1997  & 1.303 &  17.8$~\pm~$ 2.1  & 1.507 &  11.6$~\pm~$ 2.5   & 3.134 &   4.8$~\pm~$ 5.9 & 3.813 &  4.7$~\pm~$2.0  & 6.391 &  3.5$~\pm~$2.0 & 5.381 &  2.4$~\pm~$0.6\\
 1998  & 0.923 &   13.0$~\pm~$ 9.7 & 1.735 &    5.4$~\pm~$ 2.4  & 2.393 &   4.7$~\pm~$ 3.9 & 3.318 &  4.1$~\pm~$2.5  & 5.268 &  3.0$~\pm~$1.6 & 5.648 &  2.1$~\pm~$1.9\\
 1999  & 1.215 &  19.3$~\pm~$14.0  & 1.594 &   12.1$~\pm~$10.2  & 1.674 &  11.1$~\pm~$10.4 & 2.786 &  6.1$~\pm~$3.2  & 4.403 &  3.1$~\pm~$1.9 & 4.322 &  5.5$~\pm~$3.8\\
 2000  & 0.255 &   6.5$~\pm~$ 7.1  & 0.822 &  14.9$~\pm~$ 5.7   & 0.626 &  7.5$~\pm~$ 3.2  & 1.593 &  3.0$~\pm~$1.3  & 1.654 &  3.2$~\pm~$1.9 & 1.977 &  2.2$~\pm~$1.6\\
 2001  & 0.642 &  10.5$~\pm~$ 8.9  & 1.068 &   15.2$~\pm~$11.7  & 1.064 &  12.8$~\pm~$11.4 & 1.620 &  9.2$~\pm~$9.6  & 1.923 &  3.2$~\pm~$4.2 & 2.210 &  7.8$~\pm~$8.1\\
 2002  & 1.253 &   10.3$~\pm~$ 6.0 & 1.011 &  19.2$~\pm~$10.5   & 1.684 &   8.3$~\pm~$ 6.1 & 2.217 &  7.4$~\pm~$4.8  & 2.165 &  5.7$~\pm~$5.6 & 3.235 &  5.7$~\pm~$5.3\\
 2003  & 1.000 &   9.7$~\pm~$ 6.1  & 1.568 &    7.8$~\pm~$ 2.6  & 1.515 &   4.6$~\pm~$ 2.1 & 2.715 &  5.2$~\pm~$3.4  & 2.627 &  4.1$~\pm~$2.5 & 4.347 &  4.5$~\pm~$3.3\\
 2004  & 1.161 &    9.5$~\pm~$ 6.5 & 1.427 &   12.4$~\pm~$ 7.0  & 1.568 &   8.1$~\pm~$ 6.2 & 1.861 &  5.1$~\pm~$3.7  & 2.062 &  6.7$~\pm~$5.7 & 2.841 &  3.3$~\pm~$1.9\\
 2005  & 1.062 &    3.8$~\pm~$ 3.8 & 0.969 &   10.5$~\pm~$13.0  & 1.458 &   3.5$~\pm~$ 2.3 & 1.535 &  3.4$~\pm~$2.3  & 1.818 &  3.5$~\pm~$3.2 & 2.609 &  8.2$~\pm~$2.8\\
 2006  & 1.012 &   6.6$~\pm~$ 5.5  & 0.886 &    9.2$~\pm~$11.5  & 1.536 &   4.2$~\pm~$ 3.2 & 1.323 &  5.2$~\pm~$4.1  & 2.024 &  3.1$~\pm~$3.1 & 2.841 &  2.6$~\pm~$2.1\\
\hline
mean & &10.0$~\pm~$ 5.2& & 11.3$~\pm~$ 4.1& & 7.0$~\pm~$3.0& &5.5$~\pm~$1.8& & 5.2$~\pm~$3.0& & 4.6$~\pm~$2.3\\
\hline
&&&&&&\\
\hline
Year  &   \multicolumn{2}{c}{Ha(--2)}  &  \multicolumn{2}{c}{Ha(+2)}  &  \multicolumn{2}{c}{Ha(--1)}  &  \multicolumn{2}{c}{Ha(+1)}   &
 \multicolumn{2}{c}{Ha(0)}\\
 & Flux & ($e\pm \sigma$) & Flux  &(e$\pm \sigma$)& Flux & ($e\pm \sigma$)& Flux & ($e\pm \sigma$)& Flux & ($e\pm \sigma$) \\
\hline
 1996 & 36.664  & 9.4$~\pm~$6.8   & 29.766   &   11.0$~\pm~$7.0   & 45.469 &  9.1$~\pm~$6.8  & 42.018 &  11.6$~\pm~$7.6  & 48.583 &  11.1$~\pm~$7.6  &   & \\
 1997 & 33.714  & 7.0$~\pm~$8.2   & 28.349   &    8.1$~\pm~$7.1   & 43.930 &  6.8$~\pm~$7.1  & 41.554 &  7.9$~\pm~$9.2   & 48.475 &   7.4$~\pm~$8.0  &   & \\
 1998 & 27.717  & 3.5$~\pm~$3.2   & 26.397   &   4.6$~\pm~$4.0    & 34.577 &  3.5$~\pm~$3.8  & 36.438 &  6.4$~\pm~$5.5   & 39.903 &  7.3$~\pm~$4.9   &   & \\
 1999 & 29.420  & 1.7$~\pm~$2.1   & 27.907   &    1.4$~\pm~$0.8   & 37.880 &  1.5$~\pm~$0.1  & 42.658 &  3.5$~\pm~$2.6   & 48.223 &   2.5$~\pm~$2.2  &   & \\
 2000 & 15.153  & 3.9$~\pm~$4.2   & 12.928   &   4.4$~\pm~$3.7    & 19.099 &  4.6$~\pm~$3.9  & 20.783 &   6.6$~\pm~$5.7  & 22.577 &   7.5$~\pm~$6.8  &   & \\
 2001 & 11.216  & 8.1$~\pm~$6.3   &  9.774   &    8.0$~\pm~$6.2   & 13.240 &  10.4$~\pm~$8.4 & 11.934 &  10.1$~\pm~$8.4  & 13.292 &   16.2$~\pm~$13.0&   & \\
 2002 & 12.285  & 4.1$~\pm~$1.1   &  12.612  &     6.0$~\pm~$2.1  & 18.827 &  4.7$~\pm~$3.8  & 16.231 &  14.9$~\pm~$8.3  & 19.611 &  12.4$~\pm~$4.7  &   & \\
 2003 & 16.800  & 2.5$~\pm~$2.2   &  16.071  &     4.6$~\pm~$4.5  & 24.724 &  3.6$~\pm~$2.5  & 21.440 &  13.5$~\pm~$9.0  & 25.761 &    9.8$~\pm~$4.9 &   & \\
 2004 &  9.552  & 4.8$~\pm~$1.5   &  12.490  &    9.1$~\pm~$3.2   & 14.567 &  1.4$~\pm~$0.4  & 13.621 &  18.0$~\pm~$4.9  & 14.724 &   9.7$~\pm~$2.5  &   & \\
 2005 &  7.416  & 4.3$~\pm~$3.2   &  10.705  &    9.8$~\pm~$5.3   & 9.008  &  8.3$~\pm~$6.2  & 9.852  &  32.0$~\pm~$21.3 & 8.791  &   26.0$~\pm~$25.4&   & \\
 2006 &  8.489  & 2.6$~\pm~$2.9   &  13.613  &    2.6$~\pm~$2.0   & 12.402 &  4.2$~\pm~$1.6  & 12.362 &  9.3$~\pm~$4.9   & 12.101 &  12.8$~\pm~$5.6  &   & \\
\hline
mean& &4.7$~\pm~$2.4 & &  6.3$~\pm~$3.1 & & 5.3$~\pm~$3.0& & 12.2$~\pm~$7.8 & & 11.2$~\pm~$6.1 &&\\
\hline
&&&&&\\
\hline
Year  &   \multicolumn{2}{c}{Hb(--2)}  &  \multicolumn{2}{c}{Hb(+2)}  &  \multicolumn{2}{c}{Hb(--1)}  &  \multicolumn{2}{c}{Hb(+1)}   &
 \multicolumn{2}{c}{Ha(0)}\\
 & Flux & ($e\pm \sigma$) & Flux  &($e\pm \sigma$)& Flux & ($e\pm \sigma$)& Flux & ($e\pm \sigma$)& Flux & ($e\pm \sigma$) \\
\hline
 1996  & 10.383 &   7.0$~\pm~$4.5    & 8.673   &  6.2$~\pm~$1.5   & 11.245  & 6.3$~\pm~$4.5  & 11.531 & 6.7$~\pm~$2.2  & 12.884  &    7.8$~\pm~$3.9  &   &    \\
 1997  &  9.883&  3.7$~\pm~$2.3      & 8.188   &  3.3$~\pm~$3.1   & 11.509  & 4.1$~\pm~$2.5  & 10.986 & 4.0$~\pm~$3.1  & 13.094  &   4.9$~\pm~$1.1   &   &    \\
 1998  &  7.688&   2.7$~\pm~$2.5     & 7.905   &    2.1$~\pm~$1.4 &  8.515  & 2.7$~\pm~$2.9  &  9.689 & 1.7$~\pm~$1.4  & 10.530  &    1.8$~\pm~$2.1  &   &    \\
 1999  &  6.392&    4.1$~\pm~$1.9    & 6.609   &   5.1$~\pm~$2.9  &  6.829  & 6.3$~\pm~$3.9  &  8.664 & 4.8$~\pm~$3.2  &  9.542  &   6.6$~\pm~$6.8   &   &   \\
 2000  &  2.499&    2.6$~\pm~$2.0    & 2.698   &   1.7$~\pm~$1.0  &  3.105  & 3.9$~\pm~$2.5  &  3.844 & 3.0$~\pm~$1.7  &  4.193  &    5.5$~\pm~$4.6  &   &    \\
 2001  &  2.613&     4.4$~\pm~$2.5   & 2.716   &  5.6$~\pm~$5.6   &  3.220  & 4.5$~\pm~$4.0  &  3.367 & 2.5$~\pm~$1.3  &  3.772  &    8.0$~\pm~$8.5  &   &    \\
 2002  &  2.848&    5.0$~\pm~$4.2    & 3.575   &   4.9$~\pm~$3.8  &  4.058  & 5.3$~\pm~$4.2  &  4.222 & 5.3$~\pm~$4.2  &  4.873  &   6.8$~\pm~$4.6   &   &   \\
 2003  &  4.171&    4.2$~\pm~$2.1    & 4.950   &   3.0$~\pm~$1.5  &  6.619  & 2.9$~\pm~$2.9  &  6.203 & 3.4$~\pm~$3.0  &  7.277  &   4.2$~\pm~$3.2   &   &   \\
 2004  &  2.280&    5.4$~\pm~$2.5    & 3.476   &  3.3$~\pm~$2.7   &  3.402  & 4.6$~\pm~$4.6  &  3.801 & 3.5$~\pm~$3.1  &  4.153  &  3.9$~\pm~$5.3    &   &  \\
 2005  &  2.111&    4.0$~\pm~$3.4    & 3.379   &   5.0$~\pm~$2.4  &  2.790  &  4.4$~\pm~$2.5 &  3.395 & 7.7$~\pm~$2.7  &  3.193  &   9.1$~\pm~$4.1   &   &   \\
 2006  &  2.604&   2.5$~\pm~$2.5     & 3.930   &  1.2$~\pm~$0.9   &  3.007  & 2.0$~\pm~$1.7  &  4.105 & 2.3$~\pm~$1.8  &  3.686  &   3.5$~\pm~$4.0   &   &   \\
\hline
mean &  &  4.1$~\pm~$1.3 & & 3.8$~\pm~$1.7 & &   4.3$~\pm~$1.4 & & 4.1$~\pm~$1.9 & & 5.6$~\pm~$2.2 &&\\
\hline
\end{tabular}
\end{table}