-99.88% is the change from 821 to 1
Calculation steps:
[( 1 - 821 ) ÷ 821] x 100 = -99.88%
Formula
Percentage change = [(1 - 821) / 821] x 100
Subtract the new number by the original number
1 - 821 = -820
-820 ÷ 821 = -0.9987819732034104
-0.9987819732034104 x 100 = -99.88%