25.57% is the change from 661 to 830
Calculation steps:
[( 830 - 661 ) ÷ 661] x 100 = 25.57%
Formula
Percentage change = [(830 - 661) / 661] x 100
Subtract the new number by the original number
830 - 661 = 169
169 ÷ 661 = 0.2556732223903177
0.2556732223903177 x 100 = 25.57%