-19.01% is the change from 789 to 639
Calculation steps:
[( 639 - 789 ) ÷ 789] x 100 = -19.01%
Formula
Percentage change = [(639 - 789) / 789] x 100
Subtract the new number by the original number
639 - 789 = -150
-150 ÷ 789 = -0.19011406844106463
-0.19011406844106463 x 100 = -19.01%