2033.33% is the change from 15 to 320
Calculation steps:
[( 320 - 15 ) ÷ 15] x 100 = 2033.33%
Formula
Percentage change = [(320 - 15) / 15] x 100
Subtract the new number by the original number
320 - 15 = 305
305 ÷ 15 = 20.333333333333332
20.333333333333332 x 100 = 2033.33%