-40.68% is the change from 858 to 509
Calculation steps:
[( 509 - 858 ) ÷ 858] x 100 = -40.68%
Formula
Percentage change = [(509 - 858) / 858] x 100
Subtract the new number by the original number
509 - 858 = -349
-349 ÷ 858 = -0.40675990675990675
-0.40675990675990675 x 100 = -40.68%