Line chart...each line representing a different year

[#1]

I am trying to create a line chart of sales by month (x axis) with each year represented by a different line in the chart. Sales Year, Sales Month, and Gross Sales are all separate dimensions in the same table.  The table represent 4 years worth of data.  Not sure how to handle this through Expresssions. 

Any help would be appreciated.

[#2]

Can you post an example on how the data is currently displaying, and how you would like to see it displayed?

[#3]

I have attached a screen shot showing both the chart and the properties box with the expression.  The chart is showing a line for Gross Written Premium for the sum of 2009, 2010, and 2011.  I need to display each year as a separate line over the months.

[#4 · Accepted solution]

Just add another dimension for the Year,

So your dimensions would be Month, and Year.

Leave the expression as it is.

[#5]

Thanks!  That worked.