-10.49% is the change from 715 to 640
Calculation steps:
[( 640 - 715 ) ÷ 715] x 100 = -10.49%
Formula
Percentage change = [(640 - 715) / 715] x 100
Subtract the new number by the original number
640 - 715 = -75
-75 ÷ 715 = -0.1048951048951049
-0.1048951048951049 x 100 = -10.49%