-96.35% is the change from 821 to 30
Calculation steps:
[( 30 - 821 ) ÷ 821] x 100 = -96.35%
Formula
Percentage change = [(30 - 821) / 821] x 100
Subtract the new number by the original number
30 - 821 = -791
-791 ÷ 821 = -0.9634591961023142
-0.9634591961023142 x 100 = -96.35%