-90.56% is the change from 858 to 81
Calculation steps:
[( 81 - 858 ) ÷ 858] x 100 = -90.56%
Formula
Percentage change = [(81 - 858) / 858] x 100
Subtract the new number by the original number
81 - 858 = -777
-777 ÷ 858 = -0.9055944055944056
-0.9055944055944056 x 100 = -90.56%