-79.34% is the change from 639 to 132
Calculation steps:
[( 132 - 639 ) ÷ 639] x 100 = -79.34%
Formula
Percentage change = [(132 - 639) / 639] x 100
Subtract the new number by the original number
132 - 639 = -507
-507 ÷ 639 = -0.7934272300469484
-0.7934272300469484 x 100 = -79.34%