15.21% is the change from 539 to 621
Calculation steps:
[( 621 - 539 ) ÷ 539] x 100 = 15.21%
Formula
Percentage change = [(621 - 539) / 539] x 100
Subtract the new number by the original number
621 - 539 = 82
82 ÷ 539 = 0.15213358070500926
0.15213358070500926 x 100 = 15.21%