-86.53% is the change from 668 to 90
Calculation steps:
[( 90 - 668 ) ÷ 668] x 100 = -86.53%
Formula
Percentage change = [(90 - 668) / 668] x 100
Subtract the new number by the original number
90 - 668 = -578
-578 ÷ 668 = -0.8652694610778443
-0.8652694610778443 x 100 = -86.53%