-99.74% is the change from 390 to 1
Calculation steps:
[( 1 - 390 ) ÷ 390] x 100 = -99.74%
Formula
Percentage change = [(1 - 390) / 390] x 100
Subtract the new number by the original number
1 - 390 = -389
-389 ÷ 390 = -0.9974358974358974
-0.9974358974358974 x 100 = -99.74%