64.69% is the change from 388 to 639
Calculation steps:
[( 639 - 388 ) ÷ 388] x 100 = 64.69%
Formula
Percentage change = [(639 - 388) / 388] x 100
Subtract the new number by the original number
639 - 388 = 251
251 ÷ 388 = 0.6469072164948454
0.6469072164948454 x 100 = 64.69%