-89.51% is the change from 810 to 85
Calculation steps:
[( 85 - 810 ) ÷ 810] x 100 = -89.51%
Formula
Percentage change = [(85 - 810) / 810] x 100
Subtract the new number by the original number
85 - 810 = -725
-725 ÷ 810 = -0.8950617283950617
-0.8950617283950617 x 100 = -89.51%