10.39% is the change from 770 to 850
Calculation steps:
[( 850 - 770 ) ÷ 770] x 100 = 10.39%
Formula
Percentage change = [(850 - 770) / 770] x 100
Subtract the new number by the original number
850 - 770 = 80
80 ÷ 770 = 0.1038961038961039
0.1038961038961039 x 100 = 10.39%