-50.55% is the change from 819 to 405
Calculation steps:
[( 405 - 819 ) ÷ 819] x 100 = -50.55%
Formula
Percentage change = [(405 - 819) / 819] x 100
Subtract the new number by the original number
405 - 819 = -414
-414 ÷ 819 = -0.5054945054945055
-0.5054945054945055 x 100 = -50.55%