25.6% is the change from 668 to 839
Calculation steps:
[( 839 - 668 ) ÷ 668] x 100 = 25.6%
Formula
Percentage change = [(839 - 668) / 668] x 100
Subtract the new number by the original number
839 - 668 = 171
171 ÷ 668 = 0.2559880239520958
0.2559880239520958 x 100 = 25.6%