A statistical analysis of the orbital semi-major axes of Kuiper belt objects (KBOs) shows that the mass weighted mean of the heliocentric distances of 528 trans-Neptunian objects (TNOs) is 43.3 AU, and that except the Plutinos (i.e., ''Little Plutos'') in the 3:2 Neptune resonance region their radial distribution is approximately a normal distribution with maximum at about 43 AU. This distribution cannot be interpreted with resonant capture mechanism. But it is similar to the radial distribution of particles in a protoplanetary nebula computed with the author's simulative quantum theory. Comparing with the normal distribution, we find that there is an absence of objects in the range between the 3:2 Neptune resonance and 43 AU. The distribution of eccentricities of the TNOs suggests that the absent objects might have been removed into the resonance region.