\begin{table}%t4
  %\centering
\par
  \caption{Multiplicity among {\it Hipparcos} members of Sco~OB2. The columns
  show the subgroup names (Upper Scorpius; Upper Centaurus Lupus; Lower
  Centaurus Crux), their distances \citep[see][]{dezeeuw1999}, the ages
  (\citealt{degeus1989}; \citealt{preibisch2002}, for US; 
Mamajek et~al. 2002 for UCL and LCC), the number
  of known single stars, binary stars, triple systems and $N>3$ systems, and
  the binary statistics (see Sect.~\ref{sec: binarystatistics}) . \label{table:
  statistics} }
  \begin{tabular}{l cc cccc cc c}
    \hline\hline
          & $D$  & Age  & $S$ & $B$ & $T$ & $>3$ & $F_{\rm M}$ & $F_{\rm NS}$ & $F_{\rm C}$ \\
          & (pc) &(Myr) & \\
    \hline
    US    & 145  & 5--6     & 63    & 46    & 7     & 3     & 0.47  & 0.67  & 0.61\\
    UCL   & 140  & 15--22   & 131   & 68    & 17    & 4     & 0.40  & 0.61  & 0.52\\
    LCC   & 118  & 17--23   & 112   & 54    & 13    & 0     & 0.37  & 0.57  & 0.45\\
    \hline
    all   &      &          & 303   & 171   & 37    & 7     & 0.41  & 0.61  & 0.52\\
    \hline
  \end{tabular}
  \end{table}