Dynamic Deltas between DataSetID

[cpadilla0024]

Hi. I have this measure built that appears to be working fine until a DataSetID does not have values with the Line Description on my matrix. Essentially, I am trying to get deltas between the current dataset and the one prior (BUDGET27B = BUDGET27B - BUDGET27A and so on). I have an ID tag that puts them in order and makes them easy to reference. In the example picture, Inpatient Revenue went to zero in BUDGET27N (which will return no data from our financial system), however, it shows increases of $8.8m there and going forward.

I have been trying to pound through this and I am stuck.

zz_Bridge =
VAR CurrentIteration = MAX (Data[Iteration Order ID])
VAR PriorIteration = CurrentIteration-1
RETURN
SWITCH(TRUE(),
MAX('PL Format'[Order ID]) =4, "",
MAX('PL Format'[Order ID]) =8, "",
MAX('PL Format'[Order ID]) =13, "",
MAX('PL Format'[Order ID]) =15, "",
MAX('PL Format'[Order ID]) =17, "",
MAX('PL Format'[Order ID]) =29, "",
MAX('PL Format'[Order ID]) =31, "",
MAX('PL Format'[Order ID]) =33, "",
MAX('PL Format'[Order ID]) =35, "",
MAX('PL Format'[Order ID]) =37, "",
MAX('PL Format'[Order ID]) =39, "",
MAX('PL Format'[Order ID]) =41, "",
CALCULATE (
[Amt],
REMOVEFILTERS(Data[DataSetID]),
Data[Iteration Order ID] = CurrentIteration) = "" &&
CALCULATE (
[Amt],
REMOVEFILTERS(Data[DataSetID]),
Data[Iteration Order ID] = PriorIteration) = "",
0,
CALCULATE (
[Amt],
REMOVEFILTERS(Data[DataSetID]),
Data[Iteration Order ID] = CurrentIteration) = "",
0 - CALCULATE (
[Amt],
REMOVEFILTERS(Data[DataSetID]),
Data[Iteration Order ID] = PriorIteration),
CALCULATE (
[Amt],
REMOVEFILTERS(Data[DataSetID]),
Data[Iteration Order ID] = PriorIteration) = "",
CALCULATE (
[Amt],
REMOVEFILTERS(Data[DataSetID]),
Data[Iteration Order ID] = CurrentIteration) - 0,
CALCULATE (
[Amt],
REMOVEFILTERS(Data[DataSetID]),
Data[Iteration Order ID] = CurrentIteration)-
CALCULATE (
[Amt],
REMOVEFILTERS(Data[DataSetID]),
Data[Iteration Order ID] = PriorIteration))