-22.69% is the change from 639 to 494
Calculation steps:
[( 494 - 639 ) ÷ 639] x 100 = -22.69%
Formula
Percentage change = [(494 - 639) / 639] x 100
Subtract the new number by the original number
494 - 639 = -145
-145 ÷ 639 = -0.2269170579029734
-0.2269170579029734 x 100 = -22.69%