-20.75% is the change from 800 to 634
Calculation steps:
[( 634 - 800 ) ÷ 800] x 100 = -20.75%
Formula
Percentage change = [(634 - 800) / 800] x 100
Subtract the new number by the original number
634 - 800 = -166
-166 ÷ 800 = -0.2075
-0.2075 x 100 = -20.75%