-9.68% is the change from 909 to 821
Calculation steps:
[( 821 - 909 ) ÷ 909] x 100 = -9.68%
Formula
Percentage change = [(821 - 909) / 909] x 100
Subtract the new number by the original number
821 - 909 = -88
-88 ÷ 909 = -0.0968096809680968
-0.0968096809680968 x 100 = -9.68%