-31.58% is the change from 931 to 637
Calculation steps:
[( 637 - 931 ) ÷ 931] x 100 = -31.58%
Formula
Percentage change = [(637 - 931) / 931] x 100
Subtract the new number by the original number
637 - 931 = -294
-294 ÷ 931 = -0.3157894736842105
-0.3157894736842105 x 100 = -31.58%