Add a target line to a bar chart with only 1 data point

[bruty]

I'm sure this has been asked many times, and I have seen various things online, but I am having trouble adding a target line into a bar chart that has only 1 data point.

I have managed to do this before where I have had multiple data points (e.g. monthly) but I am struggling to show the additional lines with the graph with only one data point (a total).

I know how to add a secondary series, but when I do this and change it to a line graph, because there is only one data point it just appears as a small dot. How do I get this to spread out across the whole existing graph?

 

[bruty]

I am using Excel 2010 if that makes any difference.