Period distribution of the BD sample from Ma & Ge (2014) and Díaz et al. (2012) which have masses of between 9 and 90 M_J orbiting solar-type stars. Top: cumulative distribution function for BDs. The ‘large P’ fits of Ma & Ge and Díaz are used to generate the BD period distributions and are referred to as P_distr = Ma & Ge and P_distr = Díaz, respectively. Bottom figure: log-binned histogram with the corresponding fit curves (bin size log₁₀(1.98)). Our simulations are limited to the indicated (non-shaded) period range 1 d < P< 5 yr. The Raimbault (in prep.) data are used for an additional bootstrap sample estimate (Sect. 5.2).