Occurrence rate of debris discs as a function of space velocity component U_rel. Top panel: histograms showing the total number of stars (grey bars) and stars with debris discs (blue bars) as a function of U_rel. Middle panel: percentage of stars that have debris discs (black dots) and the median of the logarithm of the disc fractional luminosity in each bin (red triangles) as a function of U_rel. Bottom panel: violin diagrams representing the probability density distribution of targets with and without debris discs as a function of U_rel. The white dots show the median values, and the thick black lines indicate the interval between the first and third quartiles. The horizontal width of each blue-shaded violin area corresponds to the relative frequency of the corresponding objects as a function of U_rel. To enhance visibility, the upper limit at U_rel = 303 km s⁻¹ of the first violin is not included in the figure. We see that the probability density distribution as a function of U_rel is narrower for stars with debris discs than for stars without debris discs.