-32.93% is the change from 990 to 664
Calculation steps:
[( 664 - 990 ) ÷ 990] x 100 = -32.93%
Formula
Percentage change = [(664 - 990) / 990] x 100
Subtract the new number by the original number
664 - 990 = -326
-326 ÷ 990 = -0.3292929292929293
-0.3292929292929293 x 100 = -32.93%