0.16% is the change from 638 to 639
Calculation steps:
[( 639 - 638 ) ÷ 638] x 100 = 0.16%
Formula
Percentage change = [(639 - 638) / 638] x 100
Subtract the new number by the original number
639 - 638 = 1
1 ÷ 638 = 0.001567398119122257
0.001567398119122257 x 100 = 0.16%