-97.59% is the change from 831 to 20
Calculation steps:
[( 20 - 831 ) ÷ 831] x 100 = -97.59%
Formula
Percentage change = [(20 - 831) / 831] x 100
Subtract the new number by the original number
20 - 831 = -811
-811 ÷ 831 = -0.9759326113116726
-0.9759326113116726 x 100 = -97.59%