-86.23% is the change from 639 to 88
Calculation steps:
[( 88 - 639 ) ÷ 639] x 100 = -86.23%
Formula
Percentage change = [(88 - 639) / 639] x 100
Subtract the new number by the original number
88 - 639 = -551
-551 ÷ 639 = -0.8622848200312989
-0.8622848200312989 x 100 = -86.23%