-99.51% is the change from 810 to 4
Calculation steps:
[( 4 - 810 ) ÷ 810] x 100 = -99.51%
Formula
Percentage change = [(4 - 810) / 810] x 100
Subtract the new number by the original number
4 - 810 = -806
-806 ÷ 810 = -0.9950617283950617
-0.9950617283950617 x 100 = -99.51%