Ratio ⟨F₆₀⟩_ℱ/⟨F₆₀⟩_∞ as a function of maximum observed SEP flux ℱ (see Eq. (2)) for the Weibull distribution shown in the RHS block of Table 3. Shading represents the 68% c.i. The vertical dashed lines, black and blue, with the horizontal red arrows, indicate the upper limits of the SEP flux for the space era and Holocene, respectively, i.e., the black dot and blue star in Fig. 1b.