Answer:
The percent change is 400%
Step-by-step explanation:
We know that percentage change is given by the

i.e we find the difference between the original value and current value and then divide it by original value and multiply the obtained value with 100.
a negative percentage change indicates increase in value.
so we get 4 - 20 = -16
= -4
100 = -400
hence there is an increase of 400% in the percentage which is the required percentage.