-85.03% is the change from 668 to 100
Calculation steps:
[( 100 - 668 ) ÷ 668] x 100 = -85.03%
Formula
Percentage change = [(100 - 668) / 668] x 100
Subtract the new number by the original number
100 - 668 = -568
-568 ÷ 668 = -0.8502994011976048
-0.8502994011976048 x 100 = -85.03%