20.43% is the change from 646 to 778
Calculation steps:
[( 778 - 646 ) ÷ 646] x 100 = 20.43%
Formula
Percentage change = [(778 - 646) / 646] x 100
Subtract the new number by the original number
778 - 646 = 132
132 ÷ 646 = 0.2043343653250774
0.2043343653250774 x 100 = 20.43%