-99.02% is the change from 509 to 5
Calculation steps:
[( 5 - 509 ) ÷ 509] x 100 = -99.02%
Formula
Percentage change = [(5 - 509) / 509] x 100
Subtract the new number by the original number
5 - 509 = -504
-504 ÷ 509 = -0.9901768172888016
-0.9901768172888016 x 100 = -99.02%