-98.62% is the change from 650 to 9
Calculation steps:
[( 9 - 650 ) ÷ 650] x 100 = -98.62%
Formula
Percentage change = [(9 - 650) / 650] x 100
Subtract the new number by the original number
9 - 650 = -641
-641 ÷ 650 = -0.9861538461538462
-0.9861538461538462 x 100 = -98.62%