23.7% is the change from 671 to 830
Calculation steps:
[( 830 - 671 ) ÷ 671] x 100 = 23.7%
Formula
Percentage change = [(830 - 671) / 671] x 100
Subtract the new number by the original number
830 - 671 = 159
159 ÷ 671 = 0.23695976154992549
0.23695976154992549 x 100 = 23.7%