-6.61% is the change from 545 to 509
Calculation steps:
[( 509 - 545 ) ÷ 545] x 100 = -6.61%
Formula
Percentage change = [(509 - 545) / 545] x 100
Subtract the new number by the original number
509 - 545 = -36
-36 ÷ 545 = -0.06605504587155964
-0.06605504587155964 x 100 = -6.61%