**Table 6:** Comparison of the multiplicity frequency per binary (MF/wB and MF/B) and the companion star frequency per binary (CSF/wB and CSF/B) of our work with those derived from previous multiplicity surveys among T Tauri stars in a similar separation range $\sim$ 14-1700 AU^a, and with recent numerical simulations (bottom part). Also indicated are the number of wide (separation >0 $\hbox{$.\!\!^{\prime\prime}$ }$ 5) binaries (wB), binaries (B), triples (T), quadruples (Q) and higher multiples (>4).
$\begin{displaymath}{ \begin{tabular}{llcccccr@{~$\pm$~}lr@{~$\pm$~}lr@{~$\pm$~}l... ...}{...} & 56.3 & 18.8\% & 1.38 & 0.29 \\ \hline \end{tabular}} \end{displaymath}$ ^a This range is assuming that all systems are at 140 pc. Additionally the upper limit is actually set by confusion with background/foreground stars, and varies from survey to survey. The surveys of Leinert et al. (1993), Köhler & Leinert (1998), and Ghez et al. (1997a) have set their upper limit to 12 $\hbox{$^{\prime\prime}$ }$ ( $\sim$ 1700 AU at 140 pc), while the surveys of Köhler et al. (2000b), Köhler (2001) and Ratzka et al. (2005) have upper limits of 6 $\hbox{$^{\prime\prime}$ }$ . References: L93: Leinert et al. (1993), KL98: Köhler & Leinert (1998), G97: Ghez et al. (1997a), K00: Köhler et al. (2000b), K01: Köhler (2001), R05: Ratzka et al. (2005), SD03: Sterzik & Durisen (2003), D03: Delgado-Donate et al. (2003), D04: Delgado-Donate et al. (2004), G04: Goodwin et al. (2004).

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