Line Graph - add a bar (or something) to show the value of the difference between the two lines?

[James8761]

I've put together a simple line graph, with two lines. I've added a Down Bar which fills the gap between the two lines. Is is possible to show the difference between the two lines within the bar itself. Been playing around and can't figure it out.

 

[Johnny C]

Is the bar a column or an error bar?

Either way I guess, try adding data labels to the down bar