81.37% is the change from 306 to 555
Calculation steps:
[( 555 - 306 ) ÷ 306] x 100 = 81.37%
Formula
Percentage change = [(555 - 306) / 306] x 100
Subtract the new number by the original number
555 - 306 = 249
249 ÷ 306 = 0.8137254901960784
0.8137254901960784 x 100 = 81.37%