-28.81% is the change from 899 to 640
Calculation steps:
[( 640 - 899 ) ÷ 899] x 100 = -28.81%
Formula
Percentage change = [(640 - 899) / 899] x 100
Subtract the new number by the original number
640 - 899 = -259
-259 ÷ 899 = -0.28809788654060065
-0.28809788654060065 x 100 = -28.81%