These statics are only accumulated during steady-state detection, i.e., when the keyword "steady" is on the ..tran command. It's not something of general use, since the steady-state detection is written the the SMPS products. Typically the models detect that the error amp output current has gone to zero but not due to being at the rail of compliance. Since there's ripple on this current, the model integrates it over a clock cycle. Anyway, it doesn't work for general SPICE simulations.
My advice is to ignore those fields and compute peak, average, and RMS currents/voltages, etc, from the waveforms.