-89.65% is the change from 821 to 85
Calculation steps:
[( 85 - 821 ) ÷ 821] x 100 = -89.65%
Formula
Percentage change = [(85 - 821) / 821] x 100
Subtract the new number by the original number
85 - 821 = -736
-736 ÷ 821 = -0.8964677222898904
-0.8964677222898904 x 100 = -89.65%