-86.55% is the change from 669 to 90
Calculation steps:
[( 90 - 669 ) ÷ 669] x 100 = -86.55%
Formula
Percentage change = [(90 - 669) / 669] x 100
Subtract the new number by the original number
90 - 669 = -579
-579 ÷ 669 = -0.8654708520179372
-0.8654708520179372 x 100 = -86.55%