-23.94% is the change from 639 to 486
Calculation steps:
[( 486 - 639 ) ÷ 639] x 100 = -23.94%
Formula
Percentage change = [(486 - 639) / 639] x 100
Subtract the new number by the original number
486 - 639 = -153
-153 ÷ 639 = -0.23943661971830985
-0.23943661971830985 x 100 = -23.94%