-21.32% is the change from 408 to 321
Calculation steps:
[( 321 - 408 ) ÷ 408] x 100 = -21.32%
Formula
Percentage change = [(321 - 408) / 408] x 100
Subtract the new number by the original number
321 - 408 = -87
-87 ÷ 408 = -0.21323529411764705
-0.21323529411764705 x 100 = -21.32%