-40.71% is the change from 420 to 249
Calculation steps:
[( 249 - 420 ) ÷ 420] x 100 = -40.71%
Formula
Percentage change = [(249 - 420) / 420] x 100
Subtract the new number by the original number
249 - 420 = -171
-171 ÷ 420 = -0.40714285714285714
-0.40714285714285714 x 100 = -40.71%