-49.38% is the change from 800 to 405
Calculation steps:
[( 405 - 800 ) ÷ 800] x 100 = -49.38%
Formula
Percentage change = [(405 - 800) / 800] x 100
Subtract the new number by the original number
405 - 800 = -395
-395 ÷ 800 = -0.49375
-0.49375 x 100 = -49.38%