-32.5% is the change from 800 to 540
Calculation steps:
[( 540 - 800 ) ÷ 800] x 100 = -32.5%
Formula
Percentage change = [(540 - 800) / 800] x 100
Subtract the new number by the original number
540 - 800 = -260
-260 ÷ 800 = -0.325
-0.325 x 100 = -32.5%