\begin{table}%t8
%\centering
\par
\caption {Comparisons between expressions for the basic
precession quantities.\label{tab8}}
\begin{tabular}{|l|c|l|l|l|l|l|}
\hline\hline
Source &     & \ \ \ \   $t^0$ &\ \ \ \  $t$ & \ \ \ \   $t^2$ & \ \ \ \   $t^3$ & \ \ \ \   $t^4$ \\
\hline
IAU1976 (L77)     & & & 5038.7784    & $-$1.07259 & $-$0.001147 & \\
IAU2000 		  & & & 5038.478750  & $-$1.07259 & $-$0.001147 & \\
B03               & & & 5038.478750  & $-$1.0719530 & $-$0.00114366 & 0.000132832 \\
F03        &$\psi_{\rm A}$& &  5038.478143  & $-$1.0791653 & $-$0.00110654 & 0.000129144 \\
P03$_{\rm prel}$      & & &  5038.478750  & $-$1.0790091 & $-$0.00114044   & 0.000132851 \\
P03               & & &  5038.481507  & $-$1.0790069 & $-$0.00114045   & 0.000132851 \\
\par
\hline
IAU1976 (L77)  & ~   &84381.448  &  \hspace*{0.16cm} 0.0       & 0.05127~~~~~~~& $-$0.007726 & ~~ \\
IAU2000		   & ~ &84381.448  & $-$0.025240                & 0.05127~~~~~~~& $-$0.007726 & ~~ \\
B03 & ~          &84381.4088 & $-$0.026501  & 0.0512769 & $-$0.00772723  &$-$0.000000492 \\
F03 & $\omega_{\rm A}$ &84381.4062 & $-$0.021951 & 0.0539411 & $-$0.00719621  &$+$0.000001907~ \\
P03$_{\rm prel}$& ~  &84381.406  & $-$0.025240 & 0.0512623 & $-$0.00772502 & $-$0.000000467~ \\
P03         & ~      &84381.406  & $-$0.025754  & 0.0512623 & $-$0.00772503  & $-$0.000000467~ \\
\hline
IAU1976 (L77)  & ~   & & \hspace*{0.16cm} $+$4.1976     & 0.19447    & $-$0.000179   & ~~~  \\
IAU2000     & && \hspace*{0.16cm} $+$4.1976     & 0.19447    & $-$0.000179   & ~~~  \\
B03         & ~   && \hspace*{0.16cm} $+$4.199604   & 0.1939715  &  $-$0.00022350& $-$0.000001035  \\
F03         &$P_{\rm A}$&& \hspace*{0.16cm} $+$4.197822   & 0.1939782  & $-$0.00010053  &$+$0.000000097  \\
P03         & ~   && \hspace*{0.16cm} $+$4.199094   & 0.1939873  & $-$0.00022466&  $-$0.000000912 \\
\hline
IAU1976 (L77)  & ~   & & $-$46.8150    & 0.05059   & $+$0.000344    & ~~\\
IAU2000     & && $-$46.8150    & 0.05059      & $+$0.000344    & ~~\\
B03         & ~    && $-$46.809550  & 0.0510421    & $+$0.00052228  & $-$0.000000569  \\
F03         &$Q_{\rm A}$ & &$-$46.812649  & 0.0483315    & $-$0.00000879  & $-$0.000000215  \\
P03         & ~    & &$-$46.811015  & 0.0510283    & $+$0.00052413  & $-$0.000000646  \\
\hline
IAU1976 (L77)   & ~       &84381.448 &$-$46.8150~	 & $-$0.00059  & \hspace*{0.16cm} 0.001813   &  \\
IAU2000     & ~    &84381.448 &$-$46.84024~ & $-$0.00059  & \hspace*{0.16cm} 0.001813   &  \\
B03         & ~           &84381.4088&$-$46.836051 & $-$0.0001667& \hspace*{0.16cm} 0.0019991 & $-$0.000000523\\
F03         &$\epsilon_{\rm A}$ &84381.4062&$-$46.834600 & $-$0.0001700&\hspace*{0.16cm} 0.00200000 & \\
P03$_{\rm prel}$& ~           &84381.406 &$-$46.836255 & $-$0.0001831&\hspace*{0.16cm} 0.00200340 & $-$0.000000576\\
P03         & ~           &84381.406 &$-$46.836769 & $-$0.0001831&\hspace*{0.16cm} 0.00200340 & $-$0.000000576\\
\par
\hline   
IAU1976 (L77)   & ~    &  &$+$10.5526      & $-$2.38064   & $-$0.001125 &   \\
IAU2000     & ~ & &$+$10.5526      & $-$2.38064   & $-$0.001125 &   \\
B03         & ~      & &$+$10.557686    & $-$2.3813769 & $-$0.00121258  & $+$0.000170238 \\
F03         &$\chi_{\rm A}$ & &$+$10.553205    & $-$2.3815525 & $-$0.00106446 & $-$0.000140596 \\
P03$_{\rm prel}$& ~       & &$+$10.556403    & $-$2.3814277 & $-$0.00121196 & $+$0.000170663  \\
P03         & ~       & &$+$10.556403    & $-$2.3814292 &  $-$0.00121197 & $+$0.000170663  \\
\hline
\end{tabular}
\end{table}