I am wondering motor speed with different voltage

Does anyone know the top speed at 5v for the “DC 6V 100RPM 3mm Shaft Mini Metal Gearwheel Gear Motor N20 Geared Motor”

As far as I know, the no load speed is 30 RPM.

A motor’s output speed is proportional to the input voltage. Increasing the voltage causes the motor to operate at a higher speed. However, the motor’s speed will also be affected by the motor’s design and the load.