\begin{table}%t3
%\centering
\par
\caption{Binarity data for Sco~OB2, showing the number of companion stars
  found with the different techniques. Literature data and the new companion
  stars described in this paper are included. 
  The terms "visual'', "astrometric'', and "spectroscopic'' pertain only to 
  available observations and not to in intrinsic properties of the systems.
  Note that 
  each companion of a multiple system is included individually.
  \label{table: summary}}
  \begin{tabular}{l ccccc}
    \hline \hline 
    Type & B1-B3 & B4-B9 & A & F & GKM \\ 
    \hline \multicolumn{6}{l}{Upper Scorpius} \\ 
    \hline Single stars & 3 & 13 & 20 & 17 & 10 \\ 
    Visual & 15 & 9 & 12 & 3 & 2 \\ 
    Astrometric & 0 & 3& 1& 2& 3 \\
    Spectroscopic & 11& 12& 0 & 0& 0 \\ 
    \hline \multicolumn{6}{l}{Upper Centaurus Lupus} \\ 
    \hline 
    Single stars & 3 & 22 & 41 & 43 & 22 \\ 
    Visual  & 15 & 23 & 29 & 7 & 8 \\ 
    Astrometric & 2 & 1 & 3 & 5 & 2 \\ 
    Spectroscopic & 11& 6 & 1& 1& 0 \\ 
    \hline \multicolumn{6}{l}{Lower Centaurus Crux} \\
    \hline 
    Single stars & 3 & 16 & 31 & 47 & 14 \\ 
    Visual & 7 &13 & 24 & 10 & 4 \\ 
    Astrometric & 1 & 3 & 3 & 4 & 4 \\ 
    Spectroscopic & 3 & 3& 1 & 0 & 0 \\ 
    \hline \multicolumn{6}{l}{Scorpius OB2}\\ 
    \hline 
    Single stars & 9 & 51 & 92 & 107 & 46 \\ 
    Visual & 37 & 45 & 65 & 20 &14 \\ 
    Astrometric & 3 & 7 & 7 & 11 & 9 \\ 
    Spectroscopic & 25 & 21 & 2 & 1 & 0 \\ 
    \hline  
  \end{tabular}
  \end{table}