1700% is the change from 15 to 270
Calculation steps:
[( 270 - 15 ) ÷ 15] x 100 = 1700%
Formula
Percentage change = [(270 - 15) / 15] x 100
Subtract the new number by the original number
270 - 15 = 255
255 ÷ 15 = 17
17 x 100 = 1700%
Example