3.35% is the change from 538 to 556
Calculation steps:
[( 556 - 538 ) ÷ 538] x 100 = 3.35%
Formula
Percentage change = [(556 - 538) / 538] x 100
Subtract the new number by the original number
556 - 538 = 18
18 ÷ 538 = 0.03345724907063197
0.03345724907063197 x 100 = 3.35%