-98.66% is the change from 821 to 11
Calculation steps:
[( 11 - 821 ) ÷ 821] x 100 = -98.66%
Formula
Percentage change = [(11 - 821) / 821] x 100
Subtract the new number by the original number
11 - 821 = -810
-810 ÷ 821 = -0.9866017052375152
-0.9866017052375152 x 100 = -98.66%