-31.8% is the change from 937 to 639
Calculation steps:
[( 639 - 937 ) ÷ 937] x 100 = -31.8%
Formula
Percentage change = [(639 - 937) / 937] x 100
Subtract the new number by the original number
639 - 937 = -298
-298 ÷ 937 = -0.31803628601921025
-0.31803628601921025 x 100 = -31.8%