Beaming factor η as a function of heliocentric distance r_h for the entire sample, compared with Monte-Carlo simulations assuming a rotation period of 8 h, a geometric albedo of 0.1, a uniform distribution of the polar axes on the sphere, and a random distribution of surface roughnesses. Thermal inertia Γ = 1, 2.5 and 8 MKS cases are shown here. Although Γ = 8 MKS may seem needed to account for the three points with η = 1.5–1.8 at 13–18 AU, this case underpredicts the number of low η values at r_h> 25 AU, and Γ = 2.5 MKS provides the overall best fit.