-19.08% is the change from 519 to 420
Calculation steps:
[( 420 - 519 ) ÷ 519] x 100 = -19.08%
Formula
Percentage change = [(420 - 519) / 519] x 100
Subtract the new number by the original number
420 - 519 = -99
-99 ÷ 519 = -0.1907514450867052
-0.1907514450867052 x 100 = -19.08%