KPI Target

Hi all,

I am using the KPI visual for the 1st time and I am wanting to add a calculated target, but I can't get it to work.

My dataset has a column that contains values (TimeToFill) like so (data not real):

The Value in the KPI visual is an average of the TimeToFill values.  With the Trend Axis being the MonthYear.

For the Target value, I have written the following expression:

TimeToFill-Target = 
VAR StartDate = EOMONTH(TODAY(),-14)+1
VAR EndDate = EOMONTH(TODAY(),-1)
VAR Result =
Calculate(
    AVERAGE(fact_PageUpReqData[TimeToFill-OfferAccepted]),
    DATESBETWEEN( fact_PageUpReqData[dim_FirstOfferAccepted.FirstOfferAccepted], StartDate, EndDate )
)
RETURN
Result

But this is giving me the same result as the KPI card.

What I am wanting the target to show, is the average TimeToFill over the last 13 months.  Not what it was for the last month as it is currently.

How do I achieve this?

Thanks

Carl