-18.86% is the change from 668 to 542
Calculation steps:
[( 542 - 668 ) ÷ 668] x 100 = -18.86%
Formula
Percentage change = [(542 - 668) / 668] x 100
Subtract the new number by the original number
542 - 668 = -126
-126 ÷ 668 = -0.18862275449101795
-0.18862275449101795 x 100 = -18.86%