-22.54% is the change from 639 to 495
Calculation steps:
[( 495 - 639 ) ÷ 639] x 100 = -22.54%
Formula
Percentage change = [(495 - 639) / 639] x 100
Subtract the new number by the original number
495 - 639 = -144
-144 ÷ 639 = -0.22535211267605634
-0.22535211267605634 x 100 = -22.54%