-28.92% is the change from 899 to 639
Calculation steps:
[( 639 - 899 ) ÷ 899] x 100 = -28.92%
Formula
Percentage change = [(639 - 899) / 899] x 100
Subtract the new number by the original number
639 - 899 = -260
-260 ÷ 899 = -0.289210233592881
-0.289210233592881 x 100 = -28.92%