-3.35% is the change from 538 to 520
Calculation steps:
[( 520 - 538 ) ÷ 538] x 100 = -3.35%
Formula
Percentage change = [(520 - 538) / 538] x 100
Subtract the new number by the original number
520 - 538 = -18
-18 ÷ 538 = -0.03345724907063197
-0.03345724907063197 x 100 = -3.35%