-22.9% is the change from 668 to 515
Calculation steps:
[( 515 - 668 ) ÷ 668] x 100 = -22.9%
Formula
Percentage change = [(515 - 668) / 668] x 100
Subtract the new number by the original number
515 - 668 = -153
-153 ÷ 668 = -0.22904191616766467
-0.22904191616766467 x 100 = -22.9%