-2.88% is the change from 520 to 505
Calculation steps:
[( 505 - 520 ) ÷ 520] x 100 = -2.88%
Formula
Percentage change = [(505 - 520) / 520] x 100
Subtract the new number by the original number
505 - 520 = -15
-15 ÷ 520 = -0.028846153846153848
-0.028846153846153848 x 100 = -2.88%