-35.63% is the change from 800 to 515
Calculation steps:
[( 515 - 800 ) ÷ 800] x 100 = -35.63%
Formula
Percentage change = [(515 - 800) / 800] x 100
Subtract the new number by the original number
515 - 800 = -285
-285 ÷ 800 = -0.35625
-0.35625 x 100 = -35.63%