Bethe-approximation cross section becomes a constant [@Sampson:PhysRep:2009]. Experimental measurements of EIMI starting from Fe$^{0+}$, including double ($q_f=2$), triple ($q_f=3$), and quadruple ($q_f=4$) ionization, were measured by @Shah:JPhysB:1993. Double ionization of Fe$^{0+}$ was also measured earlier by @Freund:PRA:1990. However, those measurements seem to be affected by metastable levels in the atom beam. So, we base our cross sections on the data from @Shah:JPhysB:1993. For double ionization, the parameters given in Table \[table:cross\] were derived by @Shevelko:JPhysB:2006 by performing a least squares fit to the experimental data using Equations (\[eq:shev6a\]) and (\[eq:shev6b\]). Figure \[fig:fe02\] illustrates this cross section compared to the experimental data. We found that the triple-ionization data were well fit by scaling Equation (\[eq:shevtar\]), which describes the direct ionization, and then accounting for the indirect ionization channels by adding to that the Lotz cross sections for the $3p$ and $3s$ ionization multiplied by the appropriate branching ratios from @Kaastra:AAS:1993. The quadruple-ionization cross section was well described by the fit to Equation (\[eq:shevtar\]) given by @Shevelko:JPhysB:1995. As there are no experimental data for higher order ionization processes ($q_f \geq 5$), we estimate those cross sections by assuming only indirect contributions described by the Lotz formula scaled by the branching ratios from 