20.66% is the change from 639 to 771
Calculation steps:
[( 771 - 639 ) ÷ 639] x 100 = 20.66%
Formula
Percentage change = [(771 - 639) / 639] x 100
Subtract the new number by the original number
771 - 639 = 132
132 ÷ 639 = 0.20657276995305165
0.20657276995305165 x 100 = 20.66%