-32.73% is the change from 990 to 666
Calculation steps:
[( 666 - 990 ) ÷ 990] x 100 = -32.73%
Formula
Percentage change = [(666 - 990) / 990] x 100
Subtract the new number by the original number
666 - 990 = -324
-324 ÷ 990 = -0.32727272727272727
-0.32727272727272727 x 100 = -32.73%