-11.25% is the change from 720 to 639
Calculation steps:
[( 639 - 720 ) ÷ 720] x 100 = -11.25%
Formula
Percentage change = [(639 - 720) / 720] x 100
Subtract the new number by the original number
639 - 720 = -81
-81 ÷ 720 = -0.1125
-0.1125 x 100 = -11.25%