-79.73% is the change from 819 to 166
Calculation steps:
[( 166 - 819 ) ÷ 819] x 100 = -79.73%
Formula
Percentage change = [(166 - 819) / 819] x 100
Subtract the new number by the original number
166 - 819 = -653
-653 ÷ 819 = -0.7973137973137974
-0.7973137973137974 x 100 = -79.73%