100% is the change from 402 to 804
Calculation steps:
[( 804 - 402 ) ÷ 402] x 100 = 100%
Formula
Percentage change = [(804 - 402) / 402] x 100
Subtract the new number by the original number
804 - 402 = 402
402 ÷ 402 = 1
1 x 100 = 100%
Example