-12.83% is the change from 639 to 557
Calculation steps:
[( 557 - 639 ) ÷ 639] x 100 = -12.83%
Formula
Percentage change = [(557 - 639) / 639] x 100
Subtract the new number by the original number
557 - 639 = -82
-82 ÷ 639 = -0.12832550860719874
-0.12832550860719874 x 100 = -12.83%