-50.1% is the change from 519 to 259
Calculation steps:
[( 259 - 519 ) ÷ 519] x 100 = -50.1%
Formula
Percentage change = [(259 - 519) / 519] x 100
Subtract the new number by the original number
259 - 519 = -260
-260 ÷ 519 = -0.5009633911368016
-0.5009633911368016 x 100 = -50.1%