-22.85% is the change from 827 to 638
Calculation steps:
[( 638 - 827 ) ÷ 827] x 100 = -22.85%
Formula
Percentage change = [(638 - 827) / 827] x 100
Subtract the new number by the original number
638 - 827 = -189
-189 ÷ 827 = -0.22853688029020555
-0.22853688029020555 x 100 = -22.85%