Variation of the relative angle α between the total angular momentum vectors of the Sun-planets system and the minor planets. The curve is plotted as the N most massive minor planets have been excluded in our calculations, and each dot refers to a specific object with its semimajor axis (a) and inclination (i). The case of N = 0 indicates that all the known minor planets have been taken into account. After ruling out the contamination of the three dwarf planets Eris, Pluto, and Haumea (i.e., N = 3), α drops sharply and then maintains a very small value as N continues to increase.