-20.24% is the change from 420 to 335
Calculation steps:
[( 335 - 420 ) ÷ 420] x 100 = -20.24%
Formula
Percentage change = [(335 - 420) / 420] x 100
Subtract the new number by the original number
335 - 420 = -85
-85 ÷ 420 = -0.20238095238095238
-0.20238095238095238 x 100 = -20.24%