-37.08% is the change from 809 to 509
Calculation steps:
[( 509 - 809 ) ÷ 809] x 100 = -37.08%
Formula
Percentage change = [(509 - 809) / 809] x 100
Subtract the new number by the original number
509 - 809 = -300
-300 ÷ 809 = -0.37082818294190356
-0.37082818294190356 x 100 = -37.08%