-31.97% is the change from 976 to 664
Calculation steps:
[( 664 - 976 ) ÷ 976] x 100 = -31.97%
Formula
Percentage change = [(664 - 976) / 976] x 100
Subtract the new number by the original number
664 - 976 = -312
-312 ÷ 976 = -0.319672131147541
-0.319672131147541 x 100 = -31.97%