-96.5% is the change from 515 to 18
Calculation steps:
[( 18 - 515 ) ÷ 515] x 100 = -96.5%
Formula
Percentage change = [(18 - 515) / 515] x 100
Subtract the new number by the original number
18 - 515 = -497
-497 ÷ 515 = -0.9650485436893204
-0.9650485436893204 x 100 = -96.5%