-80.39% is the change from 510 to 100
Calculation steps:
[( 100 - 510 ) ÷ 510] x 100 = -80.39%
Formula
Percentage change = [(100 - 510) / 510] x 100
Subtract the new number by the original number
100 - 510 = -410
-410 ÷ 510 = -0.803921568627451
-0.803921568627451 x 100 = -80.39%