55.25% is the change from 400 to 621
Calculation steps:
[( 621 - 400 ) ÷ 400] x 100 = 55.25%
Formula
Percentage change = [(621 - 400) / 400] x 100
Subtract the new number by the original number
621 - 400 = 221
221 ÷ 400 = 0.5525
0.5525 x 100 = 55.25%