-22.95% is the change from 828 to 638
Calculation steps:
[( 638 - 828 ) ÷ 828] x 100 = -22.95%
Formula
Percentage change = [(638 - 828) / 828] x 100
Subtract the new number by the original number
638 - 828 = -190
-190 ÷ 828 = -0.22946859903381642
-0.22946859903381642 x 100 = -22.95%