-89.9% is the change from 842 to 85
Calculation steps:
[( 85 - 842 ) ÷ 842] x 100 = -89.9%
Formula
Percentage change = [(85 - 842) / 842] x 100
Subtract the new number by the original number
85 - 842 = -757
-757 ÷ 842 = -0.8990498812351544
-0.8990498812351544 x 100 = -89.9%