Multi-line Graph?

Greetings,

I have 3 columns in a table.

Total
Source
Date

I can create a line graph with the x-axis being the date, the y axis being the total, which looks great.

But, I don't see how to create a multi-line graph with several lines, each one representing a 'source'.

I think I can work around this by creating a total column for each source, but I would have thought that there would be an easiser way to do this.

Am I overlooking something?