-75.12% is the change from 639 to 159
Calculation steps:
[( 159 - 639 ) ÷ 639] x 100 = -75.12%
Formula
Percentage change = [(159 - 639) / 639] x 100
Subtract the new number by the original number
159 - 639 = -480
-480 ÷ 639 = -0.7511737089201878
-0.7511737089201878 x 100 = -75.12%