-80.39% is the change from 821 to 161
Calculation steps:
[( 161 - 821 ) ÷ 821] x 100 = -80.39%
Formula
Percentage change = [(161 - 821) / 821] x 100
Subtract the new number by the original number
161 - 821 = -660
-660 ÷ 821 = -0.8038976857490865
-0.8038976857490865 x 100 = -80.39%