-15.11% is the change from 642 to 545
Calculation steps:
[( 545 - 642 ) ÷ 642] x 100 = -15.11%
Formula
Percentage change = [(545 - 642) / 642] x 100
Subtract the new number by the original number
545 - 642 = -97
-97 ÷ 642 = -0.15109034267912771
-0.15109034267912771 x 100 = -15.11%