-83.68% is the change from 668 to 109
Calculation steps:
[( 109 - 668 ) ÷ 668] x 100 = -83.68%
Formula
Percentage change = [(109 - 668) / 668] x 100
Subtract the new number by the original number
109 - 668 = -559
-559 ÷ 668 = -0.8368263473053892
-0.8368263473053892 x 100 = -83.68%