-93.46% is the change from 321 to 21
Calculation steps:
[( 21 - 321 ) ÷ 321] x 100 = -93.46%
Formula
Percentage change = [(21 - 321) / 321] x 100
Subtract the new number by the original number
21 - 321 = -300
-300 ÷ 321 = -0.9345794392523364
-0.9345794392523364 x 100 = -93.46%