-99.76% is the change from 420 to 1
Calculation steps:
[( 1 - 420 ) ÷ 420] x 100 = -99.76%
Formula
Percentage change = [(1 - 420) / 420] x 100
Subtract the new number by the original number
1 - 420 = -419
-419 ÷ 420 = -0.9976190476190476
-0.9976190476190476 x 100 = -99.76%