-22.16% is the change from 668 to 520
Calculation steps:
[( 520 - 668 ) ÷ 668] x 100 = -22.16%
Formula
Percentage change = [(520 - 668) / 668] x 100
Subtract the new number by the original number
520 - 668 = -148
-148 ÷ 668 = -0.2215568862275449
-0.2215568862275449 x 100 = -22.16%