Calculate % change based on slicer (not date format)

[bopeh_99]

Hi! I'm trying to create a measure to calculate the % change of value based on my slicer selections (which is not in date format). 

Here's the sample of my data. My slicer will be "Semester" and I would like to calculate the difference between value based on the selected semesters (up to all of them). For example, if i select semester AH2019 and AH2021, it will show -8% decrease. if i select AH2019, AH2020, AH2021, it will show the % change between all 3 semesters (18.57%, -22%). 

Semester	Value	% difference
AH 2019	7000
AH 2020	8300
AH 2021	6400
SS 2019	10200
SS 2020	18202
SS 2021	8100

Please kindly assist. Your help is much much appreciated.

[Ahmedx]

Please check if these results are correct.

[bopeh_99]

Hello! Yes! Similar. I am trying to show something like this and would like to add the formula for the percentage change. 

[Ahmedx]

can you explain in detail how you got it -8%
what was taken away and what was divided.
show in numbers how it turned out -8%

[bopeh_99]

-8% is (6400/7000)-1, the difference between just AH2021 and AH 2019, where 2021 is the newer value based on the year