7.21% is the change from 638 to 684
Calculation steps:
[( 684 - 638 ) ÷ 638] x 100 = 7.21%
Formula
Percentage change = [(684 - 638) / 638] x 100
Subtract the new number by the original number
684 - 638 = 46
46 ÷ 638 = 0.07210031347962383
0.07210031347962383 x 100 = 7.21%