-88.58% is the change from 639 to 73
Calculation steps:
[( 73 - 639 ) ÷ 639] x 100 = -88.58%
Formula
Percentage change = [(73 - 639) / 639] x 100
Subtract the new number by the original number
73 - 639 = -566
-566 ÷ 639 = -0.8857589984350548
-0.8857589984350548 x 100 = -88.58%