\begin{table}%t6
%\centering
\par
\caption{Comparisons between solutions for the precession of the equator and 
expressions for the precession rates.\label{tab6}}
\begin{tabular}{|l|l|l|l|l|l|l|}
\hline\hline
Source &     &$~~~~~t^0$ &~~~~ $t$ & ~~~ $t^2$ & ~~~ $t^3$ & ~~~$t^4$ \\
\hline
L77          &$\psi_{\rm A}$ &&  5038.7784 & $-$1.07259 & $-$0.001147 &  \\
(IAU1976)    &$\omega_{\rm A}$&84~381.448 & \hspace*{0.46cm}0.0 &\ \ 0.05127 & $-$0.007726 &\\
\hline
W94          &$\psi_{\rm A}$ && 5038.456501  & $-$1.078977 & $-$0.001141 &\ \ 0.000133  \\
             &$\omega_{\rm A}$&84~381.409& $\hspace*{0.22cm}-$0.0244 &\ \ 0.051268 & $-$0.007727 &\ \ 0.000000 \\
\hline
IAU2000		 &$\psi_{\rm A}$&& 5038.478750  & $-$1.07259 & $-$0.001147 & \\
		    &$\omega_{\rm A}$&84381.448& $\hspace*{0.22cm}-$0.02524 &\ \ 0.05127 & $-$0.007726 &\\
\hline
P03$_{\rm prel}$ & $\psi_{\rm A}$ &&  5038.478750 & $-$1.0790091 & $-$0.00114044 &\ \ 0.000132851 \\
             &$\omega_{\rm A}$ &84~381.406& \hspace*{0.22cm}$-$0.02524  &\ \ 0.0512623 &
             $-$0.00772502 & $-$0.000000467  \\
\hline
P03             &$\psi_{\rm A}$& &  5038.481507  & $-$1.0790069 &
             $-$0.00114045 &\ \ 0.000132851 \\
            &$\omega_{\rm A}$&84~381.406 & \hspace*{0.22cm}$-$0.025754  &\ \ 0.0512623 &
             $-$0.00772503 & $-$0.000000467  \\
\hline
\hline                    
P03$_{\rm prel}$ &$r_{\psi}$  & 5038.478750 & 0.4794049 & $-$0.00013387 & $-$0.000021008 & \\
             &$r_{\epsilon}$& $-$0.025240  & $-$0.0000867 & 0.0000171 & 0.0000000005 &  \\ 
\hline
 P03         &$r_{\psi}$ & 5038.481507  & 0.4794106 & $-$0.00013388 &$-$ 0.000021008 & \\
             &$r_{\epsilon}$ & $-$0.025754 & $-$0.0000477 & 0.00000826 & 0.0000000006  & \\
\hline
\par
\end{tabular}
\end{table}