99.75% is the change from 405 to 809
Calculation steps:
[( 809 - 405 ) ÷ 405] x 100 = 99.75%
Formula
Percentage change = [(809 - 405) / 405] x 100
Subtract the new number by the original number
809 - 405 = 404
404 ÷ 405 = 0.9975308641975309
0.9975308641975309 x 100 = 99.75%