-81.96% is the change from 815 to 147
Calculation steps:
[( 147 - 815 ) ÷ 815] x 100 = -81.96%
Formula
Percentage change = [(147 - 815) / 815] x 100
Subtract the new number by the original number
147 - 815 = -668
-668 ÷ 815 = -0.8196319018404908
-0.8196319018404908 x 100 = -81.96%