505.05% is the change from 99 to 599
Calculation steps:
[( 599 - 99 ) ÷ 99] x 100 = 505.05%
Formula
Percentage change = [(599 - 99) / 99] x 100
Subtract the new number by the original number
599 - 99 = 500
500 ÷ 99 = 5.05050505050505
5.05050505050505 x 100 = 505.05%