-15.81% is the change from 645 to 543
Calculation steps:
[( 543 - 645 ) ÷ 645] x 100 = -15.81%
Formula
Percentage change = [(543 - 645) / 645] x 100
Subtract the new number by the original number
543 - 645 = -102
-102 ÷ 645 = -0.15813953488372093
-0.15813953488372093 x 100 = -15.81%