-98.2% is the change from 501 to 9
Calculation steps:
[( 9 - 501 ) ÷ 501] x 100 = -98.2%
Formula
Percentage change = [(9 - 501) / 501] x 100
Subtract the new number by the original number
9 - 501 = -492
-492 ÷ 501 = -0.9820359281437125
-0.9820359281437125 x 100 = -98.2%