Aggregate a reference line not displayed in bar chart

[PuffDaddy]

I'm trying to create  a reference line which is aggregated based on my YearQuarter date field, since this is how my bar chart is displayed. 

I'm trying to display the aggregated count of the project statuses as a reference. Hence i tried to use an expression that aggregates my status count (which basically just counts each project once) based on the Quarter. 

Here is my attempt at it: 

= Aggr(count(Status),[End Date.autoCalendar.YearQuarter])

However, this does not show up in my graph. 

Any idea why?