-3.9% is the change from 538 to 517
Calculation steps:
[( 517 - 538 ) ÷ 538] x 100 = -3.9%
Formula
Percentage change = [(517 - 538) / 538] x 100
Subtract the new number by the original number
517 - 538 = -21
-21 ÷ 538 = -0.03903345724907063
-0.03903345724907063 x 100 = -3.9%