4040% is the change from 15 to 621
Calculation steps:
[( 621 - 15 ) ÷ 15] x 100 = 4040%
Formula
Percentage change = [(621 - 15) / 15] x 100
Subtract the new number by the original number
621 - 15 = 606
606 ÷ 15 = 40.4
40.4 x 100 = 4040%
Example