Effect of background subtraction on SEP fluence for SEPEM Reference Energy Channel 6 (31.62–45.73 MeV). Black lines are the pre-background subtraction fluences while yellow lines are the fluences after subtraction of the background. The solid vertical lines correspond to the smallest event used in the optimised fitting distributions for the lognormal distribution (blue - Eq. (3)), the truncated power law (red - Eq. 4)) and the exponential cut-off power law (green - Eq. (5)) as well as the effect of applying the minimum value as a free parameter in the fit for the two power laws (dashed lines - see text for details).