399.02% is the change from 102 to 509
Calculation steps:
[( 509 - 102 ) ÷ 102] x 100 = 399.02%
Formula
Percentage change = [(509 - 102) / 102] x 100
Subtract the new number by the original number
509 - 102 = 407
407 ÷ 102 = 3.9901960784313726
3.9901960784313726 x 100 = 399.02%