-20.81% is the change from 668 to 529
Calculation steps:
[( 529 - 668 ) ÷ 668] x 100 = -20.81%
Formula
Percentage change = [(529 - 668) / 668] x 100
Subtract the new number by the original number
529 - 668 = -139
-139 ÷ 668 = -0.20808383233532934
-0.20808383233532934 x 100 = -20.81%