GOES fluences of 4 PAMELA documented SPEs plotted at MBF effective energies of this work, compared with SEPEM V3 fluences and ER spectra fitted from PAMELA data. Red symbols represent fluences derived by subtracting background 1 day before the onset of the events (not the starting time showing in the figures), and blue symbols denote fluences derived by subtracting background 7 days or more (due to pre-events) before the onset of the events. SEPEM V3 data has removed background flux, so the fluences of each event obtained with different backgrounds are the same.