-73.08% is the change from 639 to 172
Calculation steps:
[( 172 - 639 ) ÷ 639] x 100 = -73.08%
Formula
Percentage change = [(172 - 639) / 639] x 100
Subtract the new number by the original number
172 - 639 = -467
-467 ÷ 639 = -0.730829420970266
-0.730829420970266 x 100 = -73.08%