3100% is the change from 9 to 288
Calculation steps:
[( 288 - 9 ) ÷ 9] x 100 = 3100%
Formula
Percentage change = [(288 - 9) / 9] x 100
Subtract the new number by the original number
288 - 9 = 279
279 ÷ 9 = 31
31 x 100 = 3100%
Example