-19.9% is the change from 809 to 648
Calculation steps:
[( 648 - 809 ) ÷ 809] x 100 = -19.9%
Formula
Percentage change = [(648 - 809) / 809] x 100
Subtract the new number by the original number
648 - 809 = -161
-161 ÷ 809 = -0.19901112484548825
-0.19901112484548825 x 100 = -19.9%