-25.38% is the change from 855 to 638
Calculation steps:
[( 638 - 855 ) ÷ 855] x 100 = -25.38%
Formula
Percentage change = [(638 - 855) / 855] x 100
Subtract the new number by the original number
638 - 855 = -217
-217 ÷ 855 = -0.25380116959064325
-0.25380116959064325 x 100 = -25.38%