-18.88% is the change from 800 to 649
Calculation steps:
[( 649 - 800 ) ÷ 800] x 100 = -18.88%
Formula
Percentage change = [(649 - 800) / 800] x 100
Subtract the new number by the original number
649 - 800 = -151
-151 ÷ 800 = -0.18875
-0.18875 x 100 = -18.88%