Distributions of the field strength B_i deduced in the same MBPs as in Fig. 7. The (black) hashed histogram shows the distribution of B obtained from the SPINOR inversion code with pre-determined inclination angles (γ_p) from measurements at two heights (see main text). Other histograms illustrate the distributions of the field strength of the same magnetic features computed by inverting differently treated data and using different inversion codes (see main text) without imposing γ. The colours refer to the same inversions as in Fig. 7.