-4.68% is the change from 855 to 815
Calculation steps:
[( 815 - 855 ) ÷ 855] x 100 = -4.68%
Formula
Percentage change = [(815 - 855) / 855] x 100
Subtract the new number by the original number
815 - 855 = -40
-40 ÷ 855 = -0.04678362573099415
-0.04678362573099415 x 100 = -4.68%