-3.08% is the change from 520 to 504
Calculation steps:
[( 504 - 520 ) ÷ 520] x 100 = -3.08%
Formula
Percentage change = [(504 - 520) / 520] x 100
Subtract the new number by the original number
504 - 520 = -16
-16 ÷ 520 = -0.03076923076923077
-0.03076923076923077 x 100 = -3.08%