-9.75% is the change from 708 to 639
Calculation steps:
[( 639 - 708 ) ÷ 708] x 100 = -9.75%
Formula
Percentage change = [(639 - 708) / 708] x 100
Subtract the new number by the original number
639 - 708 = -69
-69 ÷ 708 = -0.09745762711864407
-0.09745762711864407 x 100 = -9.75%