52.25% is the change from 400 to 609
Calculation steps:
[( 609 - 400 ) ÷ 400] x 100 = 52.25%
Formula
Percentage change = [(609 - 400) / 400] x 100
Subtract the new number by the original number
609 - 400 = 209
209 ÷ 400 = 0.5225
0.5225 x 100 = 52.25%