Graduate The fractional energy loss of charged particle per radiation length

[CzTee96]

The figure usually has a caption that goes like this: "Fractional energy loss per radiation length as a function of electron or positron energy in lead," but I do not fathom is at (1/E)dE/dx =1, it seems like the particle is losing all of its energy at ~7MeV by ionisation. Therefore, I would not expect the other contributions will happen. However, the diagram seems to suggest that even at very low energy we still have losses through other processes and most bizarrely the "fractional loss" through ionisation even went greater than 1 at very low energy. For example, it seems like at 5MeV we have the "fractional energy loss per radiation length" is 1.2E! What does this even mean? Is it trying to say that the ionisation is "relatively higher" than the other processes, and the fraction of all the processes is not normalised to 1?
Also, I would expect at such a low energy the electron will lose all its energy via ionisation, but why there is still a contribution from the Bremsstrahlung at 1MeV, which is around 0.6?Source: https://cds.cern.ch/record/2315747/

 

[Vanadium 50]

Look at the units. It's per radiation length - if one loses 6% of the energy in 0.05X0, where is that on your plot?