-23.75% is the change from 838 to 639
Calculation steps:
[( 639 - 838 ) ÷ 838] x 100 = -23.75%
Formula
Percentage change = [(639 - 838) / 838] x 100
Subtract the new number by the original number
639 - 838 = -199
-199 ÷ 838 = -0.23747016706443913
-0.23747016706443913 x 100 = -23.75%