Ahhhhh, input voltage and input current, then yes! The converter is efficient!
And the laws of power state that P = U x I. So if you want the same power to the led you need less current for a higher voltage. That's why a socket has 230V on it, not just 1.
6,3V x 380mA = 2,4W
10,0V = 230mA = 2,3W
12,0V = 190mA = 2,3W
All pretty much the same. Not 100% but that's because the converter is pretty efficient but it's not 100% efficient and the efficiency depends a bit on the voltage. But it looks like the converter is more efficient on higher voltages.