Occurrence rate of brown dwarfs as companions to solar-like stars vs. orbital separation (a). Horizontal lines denote the found occurrence rates and the orbital separation range investigated while vertical lines denote the error bars. Different colors mark different studies; black is Metchev & Hillenbrand (2009); blue is Lafreniére et al. (2007), Grether & Lineweaver (2006), orange is Sahlmann et al. (2011), brown is Wittenmyer et al. (2009), violet is Patel et al. (2007), red is this study. These rather rough estimates indicate a tendency: the occurrence rate increases with increasing orbital separations.