-20.66% is the change from 668 to 530
Calculation steps:
[( 530 - 668 ) ÷ 668] x 100 = -20.66%
Formula
Percentage change = [(530 - 668) / 668] x 100
Subtract the new number by the original number
530 - 668 = -138
-138 ÷ 668 = -0.20658682634730538
-0.20658682634730538 x 100 = -20.66%