-93.33% is the change from 990 to 66
Calculation steps:
[( 66 - 990 ) ÷ 990] x 100 = -93.33%
Formula
Percentage change = [(66 - 990) / 990] x 100
Subtract the new number by the original number
66 - 990 = -924
-924 ÷ 990 = -0.9333333333333333
-0.9333333333333333 x 100 = -93.33%