-98.79% is the change from 990 to 12
Calculation steps:
[( 12 - 990 ) ÷ 990] x 100 = -98.79%
Formula
Percentage change = [(12 - 990) / 990] x 100
Subtract the new number by the original number
12 - 990 = -978
-978 ÷ 990 = -0.9878787878787879
-0.9878787878787879 x 100 = -98.79%