Haven’t you got a plug-in energy monitor? Probably going to vary with load size, dampness, external air temp. etc. etc. I’d guess that heater would be on for less than 50{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} of time on average. Would be very interested to see comparative figures for condenser vs. vented on a per load basis.
Mike.