-96.27% is the change from 509 to 19
Calculation steps:
[( 19 - 509 ) ÷ 509] x 100 = -96.27%
Formula
Percentage change = [(19 - 509) / 509] x 100
Subtract the new number by the original number
19 - 509 = -490
-490 ÷ 509 = -0.962671905697446
-0.962671905697446 x 100 = -96.27%