81.62% is the change from 457 to 830
Calculation steps:
[( 830 - 457 ) ÷ 457] x 100 = 81.62%
Formula
Percentage change = [(830 - 457) / 457] x 100
Subtract the new number by the original number
830 - 457 = 373
373 ÷ 457 = 0.8161925601750547
0.8161925601750547 x 100 = 81.62%