-19.78% is the change from 809 to 649
Calculation steps:
[( 649 - 809 ) ÷ 809] x 100 = -19.78%
Formula
Percentage change = [(649 - 809) / 809] x 100
Subtract the new number by the original number
649 - 809 = -160
-160 ÷ 809 = -0.19777503090234858
-0.19777503090234858 x 100 = -19.78%