-19.24% is the change from 821 to 663
Calculation steps:
[( 663 - 821 ) ÷ 821] x 100 = -19.24%
Formula
Percentage change = [(663 - 821) / 821] x 100
Subtract the new number by the original number
663 - 821 = -158
-158 ÷ 821 = -0.19244823386114496
-0.19244823386114496 x 100 = -19.24%