307.07% is the change from 99 to 403
Calculation steps:
[( 403 - 99 ) ÷ 99] x 100 = 307.07%
Formula
Percentage change = [(403 - 99) / 99] x 100
Subtract the new number by the original number
403 - 99 = 304
304 ÷ 99 = 3.0707070707070705
3.0707070707070705 x 100 = 307.07%