-0.49% is the change from 819 to 815
Calculation steps:
[( 815 - 819 ) ÷ 819] x 100 = -0.49%
Formula
Percentage change = [(815 - 819) / 819] x 100
Subtract the new number by the original number
815 - 819 = -4
-4 ÷ 819 = -0.004884004884004884
-0.004884004884004884 x 100 = -0.49%