71.29% is the change from 310 to 531
Calculation steps:
[( 531 - 310 ) ÷ 310] x 100 = 71.29%
Formula
Percentage change = [(531 - 310) / 310] x 100
Subtract the new number by the original number
531 - 310 = 221
221 ÷ 310 = 0.7129032258064516
0.7129032258064516 x 100 = 71.29%