-99.63% is the change from 821 to 3
Calculation steps:
[( 3 - 821 ) ÷ 821] x 100 = -99.63%
Formula
Percentage change = [(3 - 821) / 821] x 100
Subtract the new number by the original number
3 - 821 = -818
-818 ÷ 821 = -0.9963459196102314
-0.9963459196102314 x 100 = -99.63%