-80.59% is the change from 819 to 159
Calculation steps:
[( 159 - 819 ) ÷ 819] x 100 = -80.59%
Formula
Percentage change = [(159 - 819) / 819] x 100
Subtract the new number by the original number
159 - 819 = -660
-660 ÷ 819 = -0.8058608058608059
-0.8058608058608059 x 100 = -80.59%