Comparison of the differences between the HI-deficiencies of Virgo cluster galaxies derived using the D₂₅ and L_B relations of this work (grey bars) and the differences using the HG84 relations (unfilled bars). The Gaussian fit to our values is shown with the grey solid line, the fit to the HG84 values is shown with the solid black line. A third Gaussian with zero mean and a width taken to be the average of the two fits, is shown for comparison by the dotted line.