-34.07% is the change from 819 to 540
Calculation steps:
[( 540 - 819 ) ÷ 819] x 100 = -34.07%
Formula
Percentage change = [(540 - 819) / 819] x 100
Subtract the new number by the original number
540 - 819 = -279
-279 ÷ 819 = -0.34065934065934067
-0.34065934065934067 x 100 = -34.07%