-20.94% is the change from 406 to 321
Calculation steps:
[( 321 - 406 ) ÷ 406] x 100 = -20.94%
Formula
Percentage change = [(321 - 406) / 406] x 100
Subtract the new number by the original number
321 - 406 = -85
-85 ÷ 406 = -0.20935960591133004
-0.20935960591133004 x 100 = -20.94%