4.93% is the change from 609 to 639
Calculation steps:
[( 639 - 609 ) ÷ 609] x 100 = 4.93%
Formula
Percentage change = [(639 - 609) / 609] x 100
Subtract the new number by the original number
639 - 609 = 30
30 ÷ 609 = 0.04926108374384237
0.04926108374384237 x 100 = 4.93%