-40.37% is the change from 815 to 486
Calculation steps:
[( 486 - 815 ) ÷ 815] x 100 = -40.37%
Formula
Percentage change = [(486 - 815) / 815] x 100
Subtract the new number by the original number
486 - 815 = -329
-329 ÷ 815 = -0.403680981595092
-0.403680981595092 x 100 = -40.37%