I'm sure I'm missing something obvious but it has so far eluded me.

My current report:
==================

* I have a dataset of employees' absences at my company.
* It is essentially broken down by department, date and time lost.
* I have charted this as below:

![current](https://i.stack.imgur.com/EmSmO.jpg)

* The manager is shown their own departments dynamically using a **filter** on the **series group**.
* By using a report level filter I can cache the dataset overnight for all departments.

My preferred report:
====================

* In order to give some context to the data I would really like to add another line showing the same data for the whole organisation.
* This data is already captured and I can add that "department" for all users so they get a graph as below (new line in blue with square markers):
![preferred](https://i.stack.imgur.com/QLwo4.jpg)
* The trouble is that I want the extra line to appear completely differently to the existing lines

	1. **I don't want the extra line to have markers necessarily**
	2. **I don't want the extra line to appear in the same legend**
	3. **I don't want the extra line to have an action (i.e. be clickable)**

In my perfect world, there wouldn't even be a line, just a change in background colour above and below where the line would be. I haven't been able to find a pretty example of what I am talking about so instead I have produced this hideous travesty in ms paint:

![travesty](https://i.stack.imgur.com/Ynkkh.jpg)

Any help gratefully received!