Question about ASUS RT-AC68U, AC1900 AiMesh

I have been using the ASUS router since mid-April 15 and am very satisfied with it. My RT-AC68U consumes 18.5 watts in normal operation (no USB devices connected). Without WIFI, the power consumption is 13.9 watts. I am not aware of a standby mode. The power data were measured with a PM 230 burner chair.