Posterior distributions obtained for the frequency of bound binary companions from the MCMC analysis, in cases of 0 (blue) and 1 (red) detection in our survey. Frequencies were derived over separation ranges of 0.5−100 au and mass ratios of q = 0.05−1. The red dashed line shows the peak of the posterior density in the 1-detection scenario, at 7.3%, while only an upper limit was obtained in the 0-detection case. The shaded areas correspond to the 68% confidence intervals.