Observed number of BL Lacs (black solid line) versus radio power. The blue histogram represents the predicted number of objects in our volume extrapolating the RLF derived for our sample to low radio luminosities (green line in Fig. 16) and multiplied by the selection function (red line in Fig. 15). The gray histogram shows the effects of the inclusion of the five objects located in the wedge. The red histogram displays the same quantity as for a RLF with B = 1.75 and with a break at log P_r = 24.5 [W Hz^-1], below which the RLF slope is B1 = 0.