-49.15% is the change from 828 to 421
Calculation steps:
[( 421 - 828 ) ÷ 828] x 100 = -49.15%
Formula
Percentage change = [(421 - 828) / 828] x 100
Subtract the new number by the original number
421 - 828 = -407
-407 ÷ 828 = -0.4915458937198068
-0.4915458937198068 x 100 = -49.15%