Parts a, b, e, f, i and j are plots of probability distribution functions of (P_α/P_o) as a function of F and beneath each (parts c, d, g, h, k and l) is the corresponding plot of the normalized am amplification factor, [am/P_α]_n = (am/〈am〉_all)/(P_α/P_o), as a function of F and in the same (P_α/P_o) bins as the p.d.f.s. The left hand panels are for IMF [B_Y]_GSEQ < 0, the right hand panels are for IMF [B_Y]_GSEQ > 0. The plots are in 3 groups of 4: parts a-d are for the lower tercile of the simultaneous (allowing for the propagation lag) solar wind dynamic pressure, p_SW < q(0.33); parts e-h are for the middle tercile of the simultaneous solar wind dynamic pressure, q(0.33 ≤ p_SW < q(0.67); parts i-l are for the upper tercile of the simultaneous solar wind dynamic pressure, p_SW ≥ q(0.67), where q(x) is the xth quantile of the overall distribution of p_SW values.