18.21% is the change from 280 to 331
Calculation steps:
[( 331 - 280 ) ÷ 280] x 100 = 18.21%
Formula
Percentage change = [(331 - 280) / 280] x 100
Subtract the new number by the original number
331 - 280 = 51
51 ÷ 280 = 0.18214285714285713
0.18214285714285713 x 100 = 18.21%