31.58% is the change from 304 to 400
Calculation steps:
[( 400 - 304 ) ÷ 304] x 100 = 31.58%
Formula
Percentage change = [(400 - 304) / 304] x 100
Subtract the new number by the original number
400 - 304 = 96
96 ÷ 304 = 0.3157894736842105
0.3157894736842105 x 100 = 31.58%