22.9% is the change from 668 to 821
Calculation steps:
[( 821 - 668 ) ÷ 668] x 100 = 22.9%
Formula
Percentage change = [(821 - 668) / 668] x 100
Subtract the new number by the original number
821 - 668 = 153
153 ÷ 668 = 0.22904191616766467
0.22904191616766467 x 100 = 22.9%