39.6% is the change from 399 to 557
Calculation steps:
[( 557 - 399 ) ÷ 399] x 100 = 39.6%
Formula
Percentage change = [(557 - 399) / 399] x 100
Subtract the new number by the original number
557 - 399 = 158
158 ÷ 399 = 0.39598997493734334
0.39598997493734334 x 100 = 39.6%