-84.39% is the change from 519 to 81
Calculation steps:
[( 81 - 519 ) ÷ 519] x 100 = -84.39%
Formula
Percentage change = [(81 - 519) / 519] x 100
Subtract the new number by the original number
81 - 519 = -438
-438 ÷ 519 = -0.8439306358381503
-0.8439306358381503 x 100 = -84.39%