100% is the change from 409 to 818
Calculation steps:
[( 818 - 409 ) ÷ 409] x 100 = 100%
Formula
Percentage change = [(818 - 409) / 409] x 100
Subtract the new number by the original number
818 - 409 = 409
409 ÷ 409 = 1
1 x 100 = 100%
Example