-81.58% is the change from 543 to 100
Calculation steps:
[( 100 - 543 ) ÷ 543] x 100 = -81.58%
Formula
Percentage change = [(100 - 543) / 543] x 100
Subtract the new number by the original number
100 - 543 = -443
-443 ÷ 543 = -0.8158379373848987
-0.8158379373848987 x 100 = -81.58%