Display two series in one chart

[juanemilio.llopis]

Good morning, 

I think I need some help with charts :)

I have a report with a table containing the incidents in a year, grouped by months. I'm also displaying some line charts with one serie correctly, for example, I have one for "Incidents in each month", another for "accomplished SLA in each month"...

I have a Parameter called "Year" in order to show only the desired year data. 

But now I need in this line charts, show the comparison between the selected year and the year before... and that is being an insufferable pain.

I have tried in the Query to add "open_date = $P{Year} OR open_date = $P{Prev_Year}" but if I do this, I can see in the table the data of the two years :(

 

Any ideas?

Thx! Juane.

[juanemilio.llopis]

Any help?

 

Thx!