-98.24% is the change from 510 to 9
Calculation steps:
[( 9 - 510 ) ÷ 510] x 100 = -98.24%
Formula
Percentage change = [(9 - 510) / 510] x 100
Subtract the new number by the original number
9 - 510 = -501
-501 ÷ 510 = -0.9823529411764705
-0.9823529411764705 x 100 = -98.24%