-88.89% is the change from 639 to 71
Calculation steps:
[( 71 - 639 ) ÷ 639] x 100 = -88.89%
Formula
Percentage change = [(71 - 639) / 639] x 100
Subtract the new number by the original number
71 - 639 = -568
-568 ÷ 639 = -0.8888888888888888
-0.8888888888888888 x 100 = -88.89%