32.75% is the change from 400 to 531
Calculation steps:
[( 531 - 400 ) ÷ 400] x 100 = 32.75%
Formula
Percentage change = [(531 - 400) / 400] x 100
Subtract the new number by the original number
531 - 400 = 131
131 ÷ 400 = 0.3275
0.3275 x 100 = 32.75%