25.91% is the change from 660 to 831
Calculation steps:
[( 831 - 660 ) ÷ 660] x 100 = 25.91%
Formula
Percentage change = [(831 - 660) / 660] x 100
Subtract the new number by the original number
831 - 660 = 171
171 ÷ 660 = 0.2590909090909091
0.2590909090909091 x 100 = 25.91%