-48.6% is the change from 819 to 421
Calculation steps:
[( 421 - 819 ) ÷ 819] x 100 = -48.6%
Formula
Percentage change = [(421 - 819) / 819] x 100
Subtract the new number by the original number
421 - 819 = -398
-398 ÷ 819 = -0.48595848595848595
-0.48595848595848595 x 100 = -48.6%