\begin{table}%t4
%\centering
\par
   \caption{Number of multiple-planet systems detected and measured by Gaia.\label{nmult}}
\par
      \begin{tabular}{lc}
       \hline\hline\noalign{\smallskip}
        Case & Number of Systems \\
              \noalign{\smallskip}
       \hline
       \noalign{\smallskip}
1) Detection & $\sim$$ 1000$\\ 
2) Orbits and masses to  & \\ 
better than $15{-}20\%$ accuracy & $\sim$$ 400{-}500$ \\
3) Successful  & \\
coplanarity tests & $\sim $$150$\\
      \hline\noalign{\smallskip}
   \end{tabular}
\par
\end{table}