Finite-difference time-domain simulations of reverberation chambers exhibit a strong frequency dependence of field/power fluctuations on distributed losses. The performances of a reverberation chamber are calculated at different loss conditions and in a wide frequency band in terms of backscatter coefficient, and number of independent positions. Those performance indicators are related to field and power statistics through the scattering coefficients. A goodness-of-fit test is applied to analyze the statistical distribution functions of the numerical transmission scattering coefficient. Strong deviations from idealized distribution functions, some unexpected, are observed varying the chamber loading at both low- and high-frequencies. Observ...