-33.13% is the change from 815 to 545
Calculation steps:
[( 545 - 815 ) ÷ 815] x 100 = -33.13%
Formula
Percentage change = [(545 - 815) / 815] x 100
Subtract the new number by the original number
545 - 815 = -270
-270 ÷ 815 = -0.3312883435582822
-0.3312883435582822 x 100 = -33.13%