Comparison between the possible values of the superfluid moment of inertia fraction I_v(n_B)/I and the possible values of x₂ according to its posterior distribution P(x₂). We plot the points (I_v(n_B)/I,  n_B), where the baryon density n_B is expressed in units of the nuclear saturation density n₀  =  0.17 fm⁻³. The inner-crust, i.e. n_d <  n_B  ≲  0.5n₀, corresponds to the orange-shaded region. The upper panel refers to the BSk21 EoS (Goriely et al. 2010), the lower one to the SLy4 EoS (Douchin & Haensel 2001). The curves represent the points (I_v(n_B)/I,  n_B) when entrainment corrections are included (red-dashed) by using the values calculated by Chamel & Haensel (2006) and Chamel (2012) and when entrainment coupling is set to zero (gray-solid). The posterior P(x₂) is superimposed as a background histogram, with the 16th, 50th and 84th percentiles shown with black dotted lines. The two green dash-dotted lines indicate an upper limit (corresponding to the 84th percentile) to the extension of the superfluid 2 region if the mass of the Vela is M = 2M_⊙.