2900% is the change from 15 to 450
Calculation steps:
[( 450 - 15 ) ÷ 15] x 100 = 2900%
Formula
Percentage change = [(450 - 15) / 15] x 100
Subtract the new number by the original number
450 - 15 = 435
435 ÷ 15 = 29
29 x 100 = 2900%
Example