-88.17% is the change from 668 to 79
Calculation steps:
[( 79 - 668 ) ÷ 668] x 100 = -88.17%
Formula
Percentage change = [(79 - 668) / 668] x 100
Subtract the new number by the original number
79 - 668 = -589
-589 ÷ 668 = -0.8817365269461078
-0.8817365269461078 x 100 = -88.17%