230% is the change from 30 to 99
Calculation steps:
[( 99 - 30 ) ÷ 30] x 100 = 230%
Formula
Percentage change = [(99 - 30) / 30] x 100
Subtract the new number by the original number
99 - 30 = 69
69 ÷ 30 = 2.3
2.3 x 100 = 230%
Example