I_P ∝ V_CME^γ relation for E > 10 MeV, with γ = 5.09 ± 0.78. The dashed black line corresponds to the upper limit of I_P in terms of V_CME with γ = 5. The upper point in our sample corresponds to the SEP event on 8 November 2000 (see the relevant appendix in part I) and is used for the scaling. It is labeled with a red dot. In addition, the event on 15 April 2001 is highlighted with a magenta dot (see details in the text).