Xiaoming had four different set-ups, W, X, Y and Z, each with a different number of bulbs connected in series in a circuit. All the bulbs were similar and the number of batteries used was the same in the circuit.

He recorded the brightness of each bulb as shown in the table below.

Set-upsWXYZ
Brightness of each bulb (units)3725

 

Arrange the set-ups with the most number of bulbs at the top to the least number of bulbs at the bottom.