20.97% is the change from 639 to 773
Calculation steps:
[( 773 - 639 ) ÷ 639] x 100 = 20.97%
Formula
Percentage change = [(773 - 639) / 639] x 100
Subtract the new number by the original number
773 - 639 = 134
134 ÷ 639 = 0.20970266040688576
0.20970266040688576 x 100 = 20.97%