-48.6% is the change from 821 to 422
Calculation steps:
[( 422 - 821 ) ÷ 821] x 100 = -48.6%
Formula
Percentage change = [(422 - 821) / 821] x 100
Subtract the new number by the original number
422 - 821 = -399
-399 ÷ 821 = -0.48599269183922045
-0.48599269183922045 x 100 = -48.6%