-21.62% is the change from 421 to 330
Calculation steps:
[( 330 - 421 ) ÷ 421] x 100 = -21.62%
Formula
Percentage change = [(330 - 421) / 421] x 100
Subtract the new number by the original number
330 - 421 = -91
-91 ÷ 421 = -0.2161520190023753
-0.2161520190023753 x 100 = -21.62%