-80.1% is the change from 834 to 166
Calculation steps:
[( 166 - 834 ) ÷ 834] x 100 = -80.1%
Formula
Percentage change = [(166 - 834) / 834] x 100
Subtract the new number by the original number
166 - 834 = -668
-668 ÷ 834 = -0.8009592326139089
-0.8009592326139089 x 100 = -80.1%