-38.21% is the change from 840 to 519
Calculation steps:
[( 519 - 840 ) ÷ 840] x 100 = -38.21%
Formula
Percentage change = [(519 - 840) / 840] x 100
Subtract the new number by the original number
519 - 840 = -321
-321 ÷ 840 = -0.3821428571428571
-0.3821428571428571 x 100 = -38.21%