-70.71% is the change from 420 to 123
Calculation steps:
[( 123 - 420 ) ÷ 420] x 100 = -70.71%
Formula
Percentage change = [(123 - 420) / 420] x 100
Subtract the new number by the original number
123 - 420 = -297
-297 ÷ 420 = -0.7071428571428572
-0.7071428571428572 x 100 = -70.71%