-98.65% is the change from 665 to 9
Calculation steps:
[( 9 - 665 ) ÷ 665] x 100 = -98.65%
Formula
Percentage change = [(9 - 665) / 665] x 100
Subtract the new number by the original number
9 - 665 = -656
-656 ÷ 665 = -0.9864661654135338
-0.9864661654135338 x 100 = -98.65%