Number density distributions for a = 150 nm ISD particles in the plane Z = 0 in 2004 − 2005 when we start their motion from the plane Z = 50 AU with the given number density (panel A) or given velocity (panel D) distribution. Panels B and C correspond to the difference between the results from panel A and the results presented in Fig. 3 (models 2 and 1, respectively). Panels E and F show the analogical difference for the results from panel D.