Applying a growth percentage to a measure result

[mike.magill]

I have a data table that has the following fields:



LocationID
EventID
CountType
Date
Count


This table shows a list of attendance counts on various dates at different locations and different events.

I already have a measure that calculates the equivalent count last year:



CALCULATE(sum('Total Attendance'[Count]),DATEADD('Date Table'[Date],-364,DAY))


I have a table of growth targets that has the following fields:



LocationID
EventID
EventType
Date
Target%


This table has a record for each time a target changes.

I want to work out a measure that identifies the applicable growth target% for a particular count on a particular date in the data table so that I can multiply this by the CountLastYr.

Here is some sample data that also includes a column showing the expected result for comparison:

8648

Can anyone help produce a measure that does what I need?