-99.51% is the change from 809 to 4
Calculation steps:
[( 4 - 809 ) ÷ 809] x 100 = -99.51%
Formula
Percentage change = [(4 - 809) / 809] x 100
Subtract the new number by the original number
4 - 809 = -805
-805 ÷ 809 = -0.9950556242274413
-0.9950556242274413 x 100 = -99.51%