  In relativistic nucleus-nucleus collisions the transverse energy per charged
particle, E_T/N_ch, increases rapidly with beam energy and remains
approximately constant at about 800 MeV for beam energies from SPS to RHIC. It
is shown that the hadron resonance gas model describes the energy dependence,
as well as the lack of centrality dependence, qualitatively. The values of
E_T/N_ch are related to the chemical freeze-out criterium E/N about 1 GeV valid
for primordial hadrons.
