-50.68% is the change from 809 to 399
Calculation steps:
[( 399 - 809 ) ÷ 809] x 100 = -50.68%
Formula
Percentage change = [(399 - 809) / 809] x 100
Subtract the new number by the original number
399 - 809 = -410
-410 ÷ 809 = -0.5067985166872683
-0.5067985166872683 x 100 = -50.68%