the anode bias current does not change with time: since charge transport in a junction diode is mainly due to diffusion, i.e. to   a non constant spatial charge carrier density caused by bias voltage, a charge Qs is stored in the device.
The anode bias current does not alter with time: since charge movement in a junction diode is mainly driven by diffusion, i.e., due to a non-uniform spatial distribution of charge carriers caused by the applied voltage, a stored charge Qs is retained within the device.