-32.06% is the change from 939 to 638
Calculation steps:
[( 638 - 939 ) ÷ 939] x 100 = -32.06%
Formula
Percentage change = [(638 - 939) / 939] x 100
Subtract the new number by the original number
638 - 939 = -301
-301 ÷ 939 = -0.32055378061767836
-0.32055378061767836 x 100 = -32.06%