-98.61% is the change from 649 to 9
Calculation steps:
[( 9 - 649 ) ÷ 649] x 100 = -98.61%
Formula
Percentage change = [(9 - 649) / 649] x 100
Subtract the new number by the original number
9 - 649 = -640
-640 ÷ 649 = -0.9861325115562404
-0.9861325115562404 x 100 = -98.61%