81.29% is the change from 171 to 310
Calculation steps:
[( 310 - 171 ) ÷ 171] x 100 = 81.29%
Formula
Percentage change = [(310 - 171) / 171] x 100
Subtract the new number by the original number
310 - 171 = 139
139 ÷ 171 = 0.8128654970760234
0.8128654970760234 x 100 = 81.29%