Line Chart showing Prior dates

Hi,

I'm trying to create a Line Chart to show the Average and also the UCL and LCL.

To calculate this, I have the following metric:

[No. of Incidents]

[Incident_Month_Year]

I also have some additional columns as well, but they aren't relevant.

I calculate the No. of Observed Months:

Observations Tot Incidents = CALCULATE( DISTINCTCOUNT('Table1'[Incident_Month_Year]),ALLEXCEPT('Table1',[Incident_Month_Year])) 

Which I use to to draw out the Average No. of Incidents Per Month

Avg Cnt Incidents = CALCULATE(sum('Table1'[Tot_#_Incidents])/[Observations Tot Incidents], ALLEXCEPT('Table1','Table1'[Incident_Month_Year])) 

Unfortunately, when I lay out the above onto a line chart, i see that the Avg Cnt Incidents and Observation Tot Incident Measures have extended themselves to dates prior to what I have in [Incident_Month_Year].

Is there any way to filter out my DAX correctly to only show those months which have data?