27.54% is the change from 501 to 639
Calculation steps:
[( 639 - 501 ) ÷ 501] x 100 = 27.54%
Formula
Percentage change = [(639 - 501) / 501] x 100
Subtract the new number by the original number
639 - 501 = 138
138 ÷ 501 = 0.2754491017964072
0.2754491017964072 x 100 = 27.54%