Group years for visualization

[rteruyas]

Good day

I'm building a report that shows Qty Sold by year as a visualization (lines)
Color (each line) represents a year
Values (measure) is Qty Sold
X Axis is WeekNo

It works fine, but now the plot tickens. I've been asked to group 3 years together as 1 line in the visualization
So for example, if I have data from 2013 to 2017
The visualization will show
- 1 line for 2017
- 1 line for 2016
- 1 line for average (2013 to 2015)

Is there a way to achieve this in report studio. I'm trying to use average([QtySold] within set[OldYears]) and then do and if to validate the year to show either that, or the value for the current year btu it's not working as I'd expect

Thanks in advance

[hespora]

Next to no experience with dimensional style reporting, but this looks like it could be adapted for your purpose: http://cognospaul.com/2017/03/06/quickie-top-5-top-4-others/