172.13% is the change from 305 to 830
Calculation steps:
[( 830 - 305 ) ÷ 305] x 100 = 172.13%
Formula
Percentage change = [(830 - 305) / 305] x 100
Subtract the new number by the original number
830 - 305 = 525
525 ÷ 305 = 1.721311475409836
1.721311475409836 x 100 = 172.13%