-31.9% is the change from 975 to 664
Calculation steps:
[( 664 - 975 ) ÷ 975] x 100 = -31.9%
Formula
Percentage change = [(664 - 975) / 975] x 100
Subtract the new number by the original number
664 - 975 = -311
-311 ÷ 975 = -0.318974358974359
-0.318974358974359 x 100 = -31.9%