-89.36% is the change from 639 to 68
Calculation steps:
[( 68 - 639 ) ÷ 639] x 100 = -89.36%
Formula
Percentage change = [(68 - 639) / 639] x 100
Subtract the new number by the original number
68 - 639 = -571
-571 ÷ 639 = -0.8935837245696401
-0.8935837245696401 x 100 = -89.36%