Posterior distributions of the heating efficiency ϵ for all the planets with T_eq > 2000 K. The colors indicate planets with T_eq < 2250 K and T_eq > 2250 K in blue and red, respectively. Six out of the seven planets shown in red favor small heating efficiency values with the most probable value close to ϵ ~ 1%. This provides evidence that the interior structure model disfavor high ϵ values and thus the decrease seen in the HEET distribution is real given our structure model.