91.5% is the change from 306 to 586
Calculation steps:
[( 586 - 306 ) ÷ 306] x 100 = 91.5%
Formula
Percentage change = [(586 - 306) / 306] x 100
Subtract the new number by the original number
586 - 306 = 280
280 ÷ 306 = 0.9150326797385621
0.9150326797385621 x 100 = 91.5%