-3.16% is the change from 538 to 521
Calculation steps:
[( 521 - 538 ) ÷ 538] x 100 = -3.16%
Formula
Percentage change = [(521 - 538) / 538] x 100
Subtract the new number by the original number
521 - 538 = -17
-17 ÷ 538 = -0.031598513011152414
-0.031598513011152414 x 100 = -3.16%