-79.66% is the change from 639 to 130
Calculation steps:
[( 130 - 639 ) ÷ 639] x 100 = -79.66%
Formula
Percentage change = [(130 - 639) / 639] x 100
Subtract the new number by the original number
130 - 639 = -509
-509 ÷ 639 = -0.7965571205007824
-0.7965571205007824 x 100 = -79.66%