-76.65% is the change from 668 to 156
Calculation steps:
[( 156 - 668 ) ÷ 668] x 100 = -76.65%
Formula
Percentage change = [(156 - 668) / 668] x 100
Subtract the new number by the original number
156 - 668 = -512
-512 ÷ 668 = -0.7664670658682635
-0.7664670658682635 x 100 = -76.65%