Weighted histogram of the magnetic field strength. For each bin of the magnetic field strength, the count number has been multiplied by the average magnetic field filling factor for this magnetic field strength α = B₁ / B, with B₁ = 28 G following the linear fit in Fig. 6. The envelope of this histogram is then , where is the average filling factor conditioned by B, and p(B) is the magnetic field PDF of Fig. 9. The linear fit corresponds to an exponential decrease of as exp( − B / B₀), with B₀ = 803 G.