-21.35% is the change from 520 to 409
Calculation steps:
[( 409 - 520 ) ÷ 520] x 100 = -21.35%
Formula
Percentage change = [(409 - 520) / 520] x 100
Subtract the new number by the original number
409 - 520 = -111
-111 ÷ 520 = -0.21346153846153845
-0.21346153846153845 x 100 = -21.35%