Two-dimensional probability density functions of cosmic-ray energy density, E_c, and plasma density, ρ, p(E_c, ρ∣Pm_s, Pm_c), with the probability density shown via the color and conditional over specific choices of Pm_s and Pm_c. The rows show runs with increasing microphysical diffusion Prandtl numbers Pm_c ∈ {0.0045, 0.45, 45, 4500}  from top to bottom. The columns show increasing ﹩{{ \mathcal M }}_{{\rm{A}}0}﹩ for sub-, trans-, and super-Alfvénic turbulence from left to right. In the top two rows and two rightmost columns (strong coupling regime) we plot E_c ∝ ρ^4/3 and E_c ∝ ρ^2/3 trendlines, representing the equation of state of a relativistic fluid and the modifications to the equation of state through streaming, respectively.