\begin{table}%t3
   \caption{Mean heliocentric velocity components (and their standard
            deviations) of the young local associations before and after adding
	    those stars belonging to TW Hya (see text).}
   \label{tab.chg_vel_YLA}
%\centering
\par
\begin{tabular}{lrrrr}
\hline
\hline\\[-3mm]
Association     & $\overline{U}$ & $\overline{V}$ & $\overline{W}$
                & $N_{\rm k}$ \\
                & (km s$^{-1}$) & (km s$^{-1}$) & (km s$^{-1}$) & \\
\hline
Tuc-Hor/GAYA    & $-10.1_{(2.4)}$ & $-20.7_{(2.3)}$ &  $-2.5_{(3.8)}$
                & 44 \\
adding stars    & $-10.2_{(2.6)}$ & $-20.5_{(2.3)}$ &  $-2.5_{(3.7)}$
                & 47 \\
\hline
$\beta$ Pic-Cap & $-10.8_{(3.4)}$ & $-15.9_{(1.2)}$ &  $-9.8_{(2.5)}$
                & 24 \\
adding stars    & $-11.2_{(3.3)}$ & $-16.3_{(1.4)}$ &  $-9.2_{(1.6)}$
                & 28 \\
\hline
$\epsilon$ Cha  &  $-8.6_{(3.6)}$ & $-18.6_{(0.8)}$ &  $-9.3_{(1.7)}$
                & 5 \\
adding stars	&  $-9.5_{(3.0)}$ & $-19.2_{(1.4)}$ &  $-8.9_{(1.9)}$
                & 9 \\
\hline
HD 141569       &  $-5.4_{(1.5)}$ & $-15.6_{(2.6)}$ &  $-4.4_{(0.8)}$
                & 2 \\
adding stars	&  $-5.2_{(1.9)}$ & $-14.3_{(2.5)}$ &  $-1.9_{(1.9)}$
                & 8 \\
\hline
\end{tabular}
\end{table}