-21.9% is the change from 822 to 642
Calculation steps:
[( 642 - 822 ) ÷ 822] x 100 = -21.9%
Formula
Percentage change = [(642 - 822) / 822] x 100
Subtract the new number by the original number
642 - 822 = -180
-180 ÷ 822 = -0.21897810218978103
-0.21897810218978103 x 100 = -21.9%